Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 27 Nov 2017, at 11:13 PM,  
>  wrote:
> 
> This is quite surprising to me too.  The externally plugged in r8153 dongle,
> was it connected over type C port or over type A port?  AFAIK Type C port is
> actually Alpine ridge pass through port.  It is not connected to XHCI 
> controller
> or USB hub.

Over the front type A port, which connects to SMSC hub then ASMedia controller.

The type C port indeed connects to AR directly, hence no such issue.

Kai-Heng

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 27 Nov 2017, at 11:13 PM,  
>  wrote:
> 
> This is quite surprising to me too.  The externally plugged in r8153 dongle,
> was it connected over type C port or over type A port?  AFAIK Type C port is
> actually Alpine ridge pass through port.  It is not connected to XHCI 
> controller
> or USB hub.

Over the front type A port, which connects to SMSC hub then ASMedia controller.

The type C port indeed connects to AR directly, hence no such issue.

Kai-Heng

RE: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Mario.Limonciello]

> -Original Message-
> From: Kai Heng Feng [mailto:kai.heng.f...@canonical.com]
> Sent: Thursday, November 23, 2017 9:44 PM
> To: Greg KH <gre...@linuxfoundation.org>
> Cc: David Miller <da...@davemloft.net>; hayesw...@realtek.co; linux-
> u...@vger.kernel.org; net...@vger.kernel.org; LKML  ker...@vger.kernel.org>; Limonciello, Mario <mario_limoncie...@dell.com>
> Subject: Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock
> 
> 
> 
> > On 23 Nov 2017, at 5:24 PM, Greg KH <gre...@linuxfoundation.org> wrote:
> >
> > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> >>
> >> What I want to do here is to finding this connection:
> >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <->
> >> ASMedia XHCI controller (PCI ID: 1b21:1142).
> >>
> >> Is there a safer way to do this?
> >
> > Nope!  You can't do that at all from within a USB driver, sorry.  As you
> > really should not care at all :)
> 
> Got it :)
> 
> The r8153 in Dell TB dock has version information, RTL_VER_05.
> We can use it to check for workaround, but many working RTL_VER_05 devices
> will also be affected.
> Do you think it’s an acceptable compromise?
> 
> >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any
> >> information to differentiate them. Hence I want to use the connection to
> >> identify if r8153 is on a Dell TB dock.
> >
> > Are you sure there is nothing different in the version or release number
> > of the device?  'lsusb -v' shows the exact same information for both
> > devices?
> 
> Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
> dongle,
> and on a RJ45 <-> USB Type-C dongle.
> 
> >> Yes. From what I know, ASMedia is working on it, but not sure how long it
> >> will take. In the meantime, I’d like to workaround this issue for the 
> >> users.
> >
> > Again, it's a host controller bug, it should be fixed there, don't try
> > to paper over the real issue in different individual drivers.
> >
> > I think I've seen various patches on the linux-usb list for this
> > controller already, have you tried them?
> 
> Yes. These patches are all in mainline Linux now.
> 
> >> Actually no.
> >> I just plugged r8153 dongle into the same hub, surprisingly the issue
> >> doesn’t happen in this scenario.
> >
> > Then something seems to be wrong with the device itself, as that would
> > be the same exact electrical/logical path, right?
> 
> I have no idea why externally plugged one doesn’t have this issue.
> Maybe it’s related how it’s wired inside the Dell TB dock...
> 
> Kai-Heng

This is quite surprising to me too.  The externally plugged in r8153 dongle,
was it connected over type C port or over type A port?  AFAIK Type C port is
actually Alpine ridge pass through port.  It is not connected to XHCI controller
or USB hub.

RE: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Mario.Limonciello]

> -Original Message-
> From: Kai Heng Feng [mailto:kai.heng.f...@canonical.com]
> Sent: Thursday, November 23, 2017 9:44 PM
> To: Greg KH 
> Cc: David Miller ; hayesw...@realtek.co; linux-
> u...@vger.kernel.org; net...@vger.kernel.org; LKML  ker...@vger.kernel.org>; Limonciello, Mario 
> Subject: Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock
> 
> 
> 
> > On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> >
> > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> >>
> >> What I want to do here is to finding this connection:
> >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <->
> >> ASMedia XHCI controller (PCI ID: 1b21:1142).
> >>
> >> Is there a safer way to do this?
> >
> > Nope!  You can't do that at all from within a USB driver, sorry.  As you
> > really should not care at all :)
> 
> Got it :)
> 
> The r8153 in Dell TB dock has version information, RTL_VER_05.
> We can use it to check for workaround, but many working RTL_VER_05 devices
> will also be affected.
> Do you think it’s an acceptable compromise?
> 
> >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any
> >> information to differentiate them. Hence I want to use the connection to
> >> identify if r8153 is on a Dell TB dock.
> >
> > Are you sure there is nothing different in the version or release number
> > of the device?  'lsusb -v' shows the exact same information for both
> > devices?
> 
> Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
> dongle,
> and on a RJ45 <-> USB Type-C dongle.
> 
> >> Yes. From what I know, ASMedia is working on it, but not sure how long it
> >> will take. In the meantime, I’d like to workaround this issue for the 
> >> users.
> >
> > Again, it's a host controller bug, it should be fixed there, don't try
> > to paper over the real issue in different individual drivers.
> >
> > I think I've seen various patches on the linux-usb list for this
> > controller already, have you tried them?
> 
> Yes. These patches are all in mainline Linux now.
> 
> >> Actually no.
> >> I just plugged r8153 dongle into the same hub, surprisingly the issue
> >> doesn’t happen in this scenario.
> >
> > Then something seems to be wrong with the device itself, as that would
> > be the same exact electrical/logical path, right?
> 
> I have no idea why externally plugged one doesn’t have this issue.
> Maybe it’s related how it’s wired inside the Dell TB dock...
> 
> Kai-Heng

This is quite surprising to me too.  The externally plugged in r8153 dongle,
was it connected over type C port or over type A port?  AFAIK Type C port is
actually Alpine ridge pass through port.  It is not connected to XHCI controller
or USB hub.

RE: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Mario.Limonciello]

> -Original Message-
> From: Kai Heng Feng [mailto:kai.heng.f...@canonical.com]
> Sent: Friday, November 24, 2017 3:00 AM
> To: Greg KH <gre...@linuxfoundation.org>
> Cc: David Miller <da...@davemloft.net>; hayesw...@realtek.co; linux-
> u...@vger.kernel.org; net...@vger.kernel.org; LKML  ker...@vger.kernel.org>; Limonciello, Mario <mario_limoncie...@dell.com>
> Subject: Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock
> 
> 
> > Also the MAC address is different, can you just trigger off of Dell's
> > MAC address space instead of the address space of the dongle device?
> 
> A really good idea, never thought of this. Thanks for the hint :)
> Still, I need to ask Dell folks to get all the answers.
> 
> Kai-Heng

The MAC address stuff is workable to tell if it's a r8153-AD (which is in Dell 
Inc Type C
dongles,  TB16 and WD15 docks).

This alone wouldn't be enough to tell if it's a TB16.  I believe you'd need to 
have an
extra check for that, but maybe this workaround can run after you verify it's 
r8153-AD
in the special MAC address handling section of r8153 driver.

RE: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Mario.Limonciello]

> -Original Message-
> From: Kai Heng Feng [mailto:kai.heng.f...@canonical.com]
> Sent: Friday, November 24, 2017 3:00 AM
> To: Greg KH 
> Cc: David Miller ; hayesw...@realtek.co; linux-
> u...@vger.kernel.org; net...@vger.kernel.org; LKML  ker...@vger.kernel.org>; Limonciello, Mario 
> Subject: Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock
> 
> 
> > Also the MAC address is different, can you just trigger off of Dell's
> > MAC address space instead of the address space of the dongle device?
> 
> A really good idea, never thought of this. Thanks for the hint :)
> Still, I need to ask Dell folks to get all the answers.
> 
> Kai-Heng

The MAC address stuff is workable to tell if it's a r8153-AD (which is in Dell 
Inc Type C
dongles,  TB16 and WD15 docks).

This alone wouldn't be enough to tell if it's a TB16.  I believe you'd need to 
have an
extra check for that, but maybe this workaround can run after you verify it's 
r8153-AD
in the special MAC address handling section of r8153 driver.

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> Also the MAC address is different, can you just trigger off of Dell's
> MAC address space instead of the address space of the dongle device?

A really good idea, never thought of this. Thanks for the hint :)
Still, I need to ask Dell folks to get all the answers.

Kai-Heng

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> Also the MAC address is different, can you just trigger off of Dell's
> MAC address space instead of the address space of the dongle device?

A really good idea, never thought of this. Thanks for the hint :)
Still, I need to ask Dell folks to get all the answers.

Kai-Heng

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 24 Nov 2017, at 4:28 PM, Greg KH  wrote:
> 
> The bcdDevice is different between the dock device and the "real"
> device, why not use that?

Yea, I’ll poke around and see if bcdDevice alone can be a good predicate.

> Then there is still a bug.  Who as ASMedia is working on this, have they
> posted anything to the linux-usb mailing list about it?

I think they are doing this internally. I’ll advice them to ask questions here 
if
they encounter any problem.

> Maybe.  Have you tried using usbmon to see what the data streams are for
> the two devices and where they have problems and diverge?  Is the dock
> device doing something different in response to something from the host
> that the "real" device does not do?

No I haven’t.
Not really sure how do debug network packets over USB. I’ll do some research
on the topic.

Kai-Heng

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 24 Nov 2017, at 4:28 PM, Greg KH  wrote:
> 
> The bcdDevice is different between the dock device and the "real"
> device, why not use that?

Yea, I’ll poke around and see if bcdDevice alone can be a good predicate.

> Then there is still a bug.  Who as ASMedia is working on this, have they
> posted anything to the linux-usb mailing list about it?

I think they are doing this internally. I’ll advice them to ask questions here 
if
they encounter any problem.

> Maybe.  Have you tried using usbmon to see what the data streams are for
> the two devices and where they have problems and diverge?  Is the dock
> device doing something different in response to something from the host
> that the "real" device does not do?

No I haven’t.
Not really sure how do debug network packets over USB. I’ll do some research
on the topic.

Kai-Heng

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Fri, Nov 24, 2017 at 09:28:05AM +0100, Greg KH wrote:
> On Fri, Nov 24, 2017 at 11:44:02AM +0800, Kai Heng Feng wrote:
> > 
> > 
> > > On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> > > 
> > > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> > >> 
> > >> What I want to do here is to finding this connection:
> > >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
> > >> ASMedia XHCI controller (PCI ID: 1b21:1142).
> > >> 
> > >> Is there a safer way to do this?
> > > 
> > > Nope!  You can't do that at all from within a USB driver, sorry.  As you
> > > really should not care at all :)
> > 
> > Got it :)
> > 
> > The r8153 in Dell TB dock has version information, RTL_VER_05.
> > We can use it to check for workaround, but many working RTL_VER_05 devices
> > will also be affected.
> > Do you think it’s an acceptable compromise?
> 
> I think all of the users of this device that is working just fine for
> them would not like that to happen :(
> 
> > >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
> > >> information to differentiate them. Hence I want to use the connection to
> > >> identify if r8153 is on a Dell TB dock.
> > > 
> > > Are you sure there is nothing different in the version or release number
> > > of the device?  'lsusb -v' shows the exact same information for both
> > > devices?
> > 
> > Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
> > dongle,
> > and on a RJ45 <-> USB Type-C dongle.
> 
> The bcdDevice is different between the dock device and the "real"
> device, why not use that?

Also the MAC address is different, can you just trigger off of Dell's
MAC address space instead of the address space of the dongle device?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Fri, Nov 24, 2017 at 09:28:05AM +0100, Greg KH wrote:
> On Fri, Nov 24, 2017 at 11:44:02AM +0800, Kai Heng Feng wrote:
> > 
> > 
> > > On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> > > 
> > > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> > >> 
> > >> What I want to do here is to finding this connection:
> > >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
> > >> ASMedia XHCI controller (PCI ID: 1b21:1142).
> > >> 
> > >> Is there a safer way to do this?
> > > 
> > > Nope!  You can't do that at all from within a USB driver, sorry.  As you
> > > really should not care at all :)
> > 
> > Got it :)
> > 
> > The r8153 in Dell TB dock has version information, RTL_VER_05.
> > We can use it to check for workaround, but many working RTL_VER_05 devices
> > will also be affected.
> > Do you think it’s an acceptable compromise?
> 
> I think all of the users of this device that is working just fine for
> them would not like that to happen :(
> 
> > >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
> > >> information to differentiate them. Hence I want to use the connection to
> > >> identify if r8153 is on a Dell TB dock.
> > > 
> > > Are you sure there is nothing different in the version or release number
> > > of the device?  'lsusb -v' shows the exact same information for both
> > > devices?
> > 
> > Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
> > dongle,
> > and on a RJ45 <-> USB Type-C dongle.
> 
> The bcdDevice is different between the dock device and the "real"
> device, why not use that?

Also the MAC address is different, can you just trigger off of Dell's
MAC address space instead of the address space of the dongle device?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Fri, Nov 24, 2017 at 11:44:02AM +0800, Kai Heng Feng wrote:
> 
> 
> > On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> > 
> > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> >> 
> >> What I want to do here is to finding this connection:
> >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
> >> ASMedia XHCI controller (PCI ID: 1b21:1142).
> >> 
> >> Is there a safer way to do this?
> > 
> > Nope!  You can't do that at all from within a USB driver, sorry.  As you
> > really should not care at all :)
> 
> Got it :)
> 
> The r8153 in Dell TB dock has version information, RTL_VER_05.
> We can use it to check for workaround, but many working RTL_VER_05 devices
> will also be affected.
> Do you think it’s an acceptable compromise?

I think all of the users of this device that is working just fine for
them would not like that to happen :(

> >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
> >> information to differentiate them. Hence I want to use the connection to
> >> identify if r8153 is on a Dell TB dock.
> > 
> > Are you sure there is nothing different in the version or release number
> > of the device?  'lsusb -v' shows the exact same information for both
> > devices?
> 
> Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
> dongle,
> and on a RJ45 <-> USB Type-C dongle.

The bcdDevice is different between the dock device and the "real"
device, why not use that?

> >> Yes. From what I know, ASMedia is working on it, but not sure how long it
> >> will take. In the meantime, I’d like to workaround this issue for the 
> >> users.
> > 
> > Again, it's a host controller bug, it should be fixed there, don't try
> > to paper over the real issue in different individual drivers.
> > 
> > I think I've seen various patches on the linux-usb list for this
> > controller already, have you tried them?
> 
> Yes. These patches are all in mainline Linux now.

Then there is still a bug.  Who as ASMedia is working on this, have they
posted anything to the linux-usb mailing list about it?

> >> Actually no.
> >> I just plugged r8153 dongle into the same hub, surprisingly the issue
> >> doesn’t happen in this scenario.
> > 
> > Then something seems to be wrong with the device itself, as that would
> > be the same exact electrical/logical path, right?
> 
> I have no idea why externally plugged one doesn’t have this issue.
> Maybe it’s related how it’s wired inside the Dell TB dock...

Maybe.  Have you tried using usbmon to see what the data streams are for
the two devices and where they have problems and diverge?  Is the dock
device doing something different in response to something from the host
that the "real" device does not do?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Fri, Nov 24, 2017 at 11:44:02AM +0800, Kai Heng Feng wrote:
> 
> 
> > On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> > 
> > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> >> 
> >> What I want to do here is to finding this connection:
> >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
> >> ASMedia XHCI controller (PCI ID: 1b21:1142).
> >> 
> >> Is there a safer way to do this?
> > 
> > Nope!  You can't do that at all from within a USB driver, sorry.  As you
> > really should not care at all :)
> 
> Got it :)
> 
> The r8153 in Dell TB dock has version information, RTL_VER_05.
> We can use it to check for workaround, but many working RTL_VER_05 devices
> will also be affected.
> Do you think it’s an acceptable compromise?

I think all of the users of this device that is working just fine for
them would not like that to happen :(

> >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
> >> information to differentiate them. Hence I want to use the connection to
> >> identify if r8153 is on a Dell TB dock.
> > 
> > Are you sure there is nothing different in the version or release number
> > of the device?  'lsusb -v' shows the exact same information for both
> > devices?
> 
> Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
> dongle,
> and on a RJ45 <-> USB Type-C dongle.

The bcdDevice is different between the dock device and the "real"
device, why not use that?

> >> Yes. From what I know, ASMedia is working on it, but not sure how long it
> >> will take. In the meantime, I’d like to workaround this issue for the 
> >> users.
> > 
> > Again, it's a host controller bug, it should be fixed there, don't try
> > to paper over the real issue in different individual drivers.
> > 
> > I think I've seen various patches on the linux-usb list for this
> > controller already, have you tried them?
> 
> Yes. These patches are all in mainline Linux now.

Then there is still a bug.  Who as ASMedia is working on this, have they
posted anything to the linux-usb mailing list about it?

> >> Actually no.
> >> I just plugged r8153 dongle into the same hub, surprisingly the issue
> >> doesn’t happen in this scenario.
> > 
> > Then something seems to be wrong with the device itself, as that would
> > be the same exact electrical/logical path, right?
> 
> I have no idea why externally plugged one doesn’t have this issue.
> Maybe it’s related how it’s wired inside the Dell TB dock...

Maybe.  Have you tried using usbmon to see what the data streams are for
the two devices and where they have problems and diverge?  Is the dock
device doing something different in response to something from the host
that the "real" device does not do?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> 
> On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
>> 
>> What I want to do here is to finding this connection:
>> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
>> ASMedia XHCI controller (PCI ID: 1b21:1142).
>> 
>> Is there a safer way to do this?
> 
> Nope!  You can't do that at all from within a USB driver, sorry.  As you
> really should not care at all :)

Got it :)

The r8153 in Dell TB dock has version information, RTL_VER_05.
We can use it to check for workaround, but many working RTL_VER_05 devices
will also be affected.
Do you think it’s an acceptable compromise?

>> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
>> information to differentiate them. Hence I want to use the connection to
>> identify if r8153 is on a Dell TB dock.
> 
> Are you sure there is nothing different in the version or release number
> of the device?  'lsusb -v' shows the exact same information for both
> devices?

Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
dongle,
and on a RJ45 <-> USB Type-C dongle.

>> Yes. From what I know, ASMedia is working on it, but not sure how long it
>> will take. In the meantime, I’d like to workaround this issue for the users.
> 
> Again, it's a host controller bug, it should be fixed there, don't try
> to paper over the real issue in different individual drivers.
> 
> I think I've seen various patches on the linux-usb list for this
> controller already, have you tried them?

Yes. These patches are all in mainline Linux now.

>> Actually no.
>> I just plugged r8153 dongle into the same hub, surprisingly the issue
>> doesn’t happen in this scenario.
> 
> Then something seems to be wrong with the device itself, as that would
> be the same exact electrical/logical path, right?

I have no idea why externally plugged one doesn’t have this issue.
Maybe it’s related how it’s wired inside the Dell TB dock...

Kai-Heng



lsusb-a
Description: Binary data


lsusb-c
Description: Binary data


lsusb-dock
Description: Binary data

> thanks,
> 
> greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 23 Nov 2017, at 5:24 PM, Greg KH  wrote:
> 
> On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
>> 
>> What I want to do here is to finding this connection:
>> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
>> ASMedia XHCI controller (PCI ID: 1b21:1142).
>> 
>> Is there a safer way to do this?
> 
> Nope!  You can't do that at all from within a USB driver, sorry.  As you
> really should not care at all :)

Got it :)

The r8153 in Dell TB dock has version information, RTL_VER_05.
We can use it to check for workaround, but many working RTL_VER_05 devices
will also be affected.
Do you think it’s an acceptable compromise?

>> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
>> information to differentiate them. Hence I want to use the connection to
>> identify if r8153 is on a Dell TB dock.
> 
> Are you sure there is nothing different in the version or release number
> of the device?  'lsusb -v' shows the exact same information for both
> devices?

Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 
dongle,
and on a RJ45 <-> USB Type-C dongle.

>> Yes. From what I know, ASMedia is working on it, but not sure how long it
>> will take. In the meantime, I’d like to workaround this issue for the users.
> 
> Again, it's a host controller bug, it should be fixed there, don't try
> to paper over the real issue in different individual drivers.
> 
> I think I've seen various patches on the linux-usb list for this
> controller already, have you tried them?

Yes. These patches are all in mainline Linux now.

>> Actually no.
>> I just plugged r8153 dongle into the same hub, surprisingly the issue
>> doesn’t happen in this scenario.
> 
> Then something seems to be wrong with the device itself, as that would
> be the same exact electrical/logical path, right?

I have no idea why externally plugged one doesn’t have this issue.
Maybe it’s related how it’s wired inside the Dell TB dock...

Kai-Heng



lsusb-a
Description: Binary data


lsusb-c
Description: Binary data


lsusb-dock
Description: Binary data

> thanks,
> 
> greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> 
> > On 23 Nov 2017, at 3:58 PM, Greg KH  wrote:
> > 
> > On Thu, Nov 23, 2017 at 01:38:38AM -0500, Kai-Heng Feng wrote:
> >> r8153 on Dell TB dock corrupts rx packets.
> >> 
> >> The root cause is not found yet, but disabling rx checksumming can
> >> workaround the issue. We can use this connection to decide if it's
> >> a Dell TB dock:
> >> Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> >> 
> >> BugLink: https://bugs.launchpad.net/bugs/1729674
> >> Cc: Mario Limonciello 
> >> Signed-off-by: Kai-Heng Feng 
> >> ---
> >> drivers/net/usb/r8152.c | 33 -
> >> 1 file changed, 32 insertions(+), 1 deletion(-)
> >> 
> >> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> >> index d51d9abf7986..58b80b5e7803 100644
> >> --- a/drivers/net/usb/r8152.c
> >> +++ b/drivers/net/usb/r8152.c
> >> @@ -27,6 +27,8 @@
> >> #include 
> >> #include 
> >> #include 
> >> +#include 
> >> +#include 
> >> 
> >> /* Information for net-next */
> >> #define NETNEXT_VERSION"09"
> >> @@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface 
> >> *intf)
> >>return version;
> >> }
> >> 
> >> +/* Ethernet on Dell TB 15/16 dock is connected this way:
> >> + * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> >> + * We use this connection to make sure r8153 is on the Dell TB dock.
> >> + */
> >> +static bool check_dell_tb_dock(struct usb_device *udev)
> >> +{
> >> +  struct usb_device *hub = udev->parent;
> >> +  struct usb_device *root_hub;
> >> +  struct pci_dev *controller;
> >> +
> >> +  if (!hub)
> >> +  return false;
> >> +
> >> +  if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
> >> +le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
> >> +  return false;
> >> +
> >> +  root_hub = hub->parent;
> >> +  if (!root_hub || root_hub->parent)
> >> +  return false;
> >> +
> >> +  controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);
> > 
> > That's a very scary, and dangerous, cast.  You can not ever be sure that
> > the hub really is a "root hub" like this.
> 
> What I want to do here is to finding this connection:
> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
> ASMedia XHCI controller (PCI ID: 1b21:1142).
> 
> Is there a safer way to do this?

Nope!  You can't do that at all from within a USB driver, sorry.  As you
really should not care at all :)

> >> +  if (controller->vendor == 0x1b21 && controller->device == 0x1142)
> >> +  return true;
> > 
> > Why can't you just look at the USB device itself and go off of a quirk
> > in it?  Something like a version or string or something else?
> 
> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
> information to differentiate them. Hence I want to use the connection to
> identify if r8153 is on a Dell TB dock.

Are you sure there is nothing different in the version or release number
of the device?  'lsusb -v' shows the exact same information for both
devices?

> > This sounds like a USB host controller issue, not a USB device issue,
> > can't we fix the "real" problem here instead of this crazy work-around?
> 
> Yes. From what I know, ASMedia is working on it, but not sure how long it
> will take. In the meantime, I’d like to workaround this issue for the users.

Again, it's a host controller bug, it should be fixed there, don't try
to paper over the real issue in different individual drivers.

I think I've seen various patches on the linux-usb list for this
controller already, have you tried them?

> > Odds are any device plugged into the hub should have the same issue,
> > right?
> 
> Actually no.
> I just plugged r8153 dongle into the same hub, surprisingly the issue
> doesn’t happen in this scenario.

Then something seems to be wrong with the device itself, as that would
be the same exact electrical/logical path, right?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote:
> 
> > On 23 Nov 2017, at 3:58 PM, Greg KH  wrote:
> > 
> > On Thu, Nov 23, 2017 at 01:38:38AM -0500, Kai-Heng Feng wrote:
> >> r8153 on Dell TB dock corrupts rx packets.
> >> 
> >> The root cause is not found yet, but disabling rx checksumming can
> >> workaround the issue. We can use this connection to decide if it's
> >> a Dell TB dock:
> >> Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> >> 
> >> BugLink: https://bugs.launchpad.net/bugs/1729674
> >> Cc: Mario Limonciello 
> >> Signed-off-by: Kai-Heng Feng 
> >> ---
> >> drivers/net/usb/r8152.c | 33 -
> >> 1 file changed, 32 insertions(+), 1 deletion(-)
> >> 
> >> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> >> index d51d9abf7986..58b80b5e7803 100644
> >> --- a/drivers/net/usb/r8152.c
> >> +++ b/drivers/net/usb/r8152.c
> >> @@ -27,6 +27,8 @@
> >> #include 
> >> #include 
> >> #include 
> >> +#include 
> >> +#include 
> >> 
> >> /* Information for net-next */
> >> #define NETNEXT_VERSION"09"
> >> @@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface 
> >> *intf)
> >>return version;
> >> }
> >> 
> >> +/* Ethernet on Dell TB 15/16 dock is connected this way:
> >> + * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> >> + * We use this connection to make sure r8153 is on the Dell TB dock.
> >> + */
> >> +static bool check_dell_tb_dock(struct usb_device *udev)
> >> +{
> >> +  struct usb_device *hub = udev->parent;
> >> +  struct usb_device *root_hub;
> >> +  struct pci_dev *controller;
> >> +
> >> +  if (!hub)
> >> +  return false;
> >> +
> >> +  if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
> >> +le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
> >> +  return false;
> >> +
> >> +  root_hub = hub->parent;
> >> +  if (!root_hub || root_hub->parent)
> >> +  return false;
> >> +
> >> +  controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);
> > 
> > That's a very scary, and dangerous, cast.  You can not ever be sure that
> > the hub really is a "root hub" like this.
> 
> What I want to do here is to finding this connection:
> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
> ASMedia XHCI controller (PCI ID: 1b21:1142).
> 
> Is there a safer way to do this?

Nope!  You can't do that at all from within a USB driver, sorry.  As you
really should not care at all :)

> >> +  if (controller->vendor == 0x1b21 && controller->device == 0x1142)
> >> +  return true;
> > 
> > Why can't you just look at the USB device itself and go off of a quirk
> > in it?  Something like a version or string or something else?
> 
> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
> information to differentiate them. Hence I want to use the connection to
> identify if r8153 is on a Dell TB dock.

Are you sure there is nothing different in the version or release number
of the device?  'lsusb -v' shows the exact same information for both
devices?

> > This sounds like a USB host controller issue, not a USB device issue,
> > can't we fix the "real" problem here instead of this crazy work-around?
> 
> Yes. From what I know, ASMedia is working on it, but not sure how long it
> will take. In the meantime, I’d like to workaround this issue for the users.

Again, it's a host controller bug, it should be fixed there, don't try
to paper over the real issue in different individual drivers.

I think I've seen various patches on the linux-usb list for this
controller already, have you tried them?

> > Odds are any device plugged into the hub should have the same issue,
> > right?
> 
> Actually no.
> I just plugged r8153 dongle into the same hub, surprisingly the issue
> doesn’t happen in this scenario.

Then something seems to be wrong with the device itself, as that would
be the same exact electrical/logical path, right?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 23 Nov 2017, at 3:58 PM, Greg KH  wrote:
> 
> On Thu, Nov 23, 2017 at 01:38:38AM -0500, Kai-Heng Feng wrote:
>> r8153 on Dell TB dock corrupts rx packets.
>> 
>> The root cause is not found yet, but disabling rx checksumming can
>> workaround the issue. We can use this connection to decide if it's
>> a Dell TB dock:
>> Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
>> 
>> BugLink: https://bugs.launchpad.net/bugs/1729674
>> Cc: Mario Limonciello 
>> Signed-off-by: Kai-Heng Feng 
>> ---
>> drivers/net/usb/r8152.c | 33 -
>> 1 file changed, 32 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
>> index d51d9abf7986..58b80b5e7803 100644
>> --- a/drivers/net/usb/r8152.c
>> +++ b/drivers/net/usb/r8152.c
>> @@ -27,6 +27,8 @@
>> #include 
>> #include 
>> #include 
>> +#include 
>> +#include 
>> 
>> /* Information for net-next */
>> #define NETNEXT_VERSION  "09"
>> @@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface *intf)
>>  return version;
>> }
>> 
>> +/* Ethernet on Dell TB 15/16 dock is connected this way:
>> + * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
>> + * We use this connection to make sure r8153 is on the Dell TB dock.
>> + */
>> +static bool check_dell_tb_dock(struct usb_device *udev)
>> +{
>> +struct usb_device *hub = udev->parent;
>> +struct usb_device *root_hub;
>> +struct pci_dev *controller;
>> +
>> +if (!hub)
>> +return false;
>> +
>> +if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
>> +  le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
>> +return false;
>> +
>> +root_hub = hub->parent;
>> +if (!root_hub || root_hub->parent)
>> +return false;
>> +
>> +controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);
> 
> That's a very scary, and dangerous, cast.  You can not ever be sure that
> the hub really is a "root hub" like this.

What I want to do here is to finding this connection:
Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
ASMedia XHCI controller (PCI ID: 1b21:1142).

Is there a safer way to do this?

> 
>> +if (controller->vendor == 0x1b21 && controller->device == 0x1142)
>> +return true;
> 
> Why can't you just look at the USB device itself and go off of a quirk
> in it?  Something like a version or string or something else?

I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
information to differentiate them. Hence I want to use the connection to
identify if r8153 is on a Dell TB dock.

> 
> This sounds like a USB host controller issue, not a USB device issue,
> can't we fix the "real" problem here instead of this crazy work-around?

Yes. From what I know, ASMedia is working on it, but not sure how long it
will take. In the meantime, I’d like to workaround this issue for the users.

> Odds are any device plugged into the hub should have the same issue,
> right?

Actually no.
I just plugged r8153 dongle into the same hub, surprisingly the issue
doesn’t happen in this scenario.

Kai-Heng

> 
> thanks,
> 
> greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai Heng Feng]

> On 23 Nov 2017, at 3:58 PM, Greg KH  wrote:
> 
> On Thu, Nov 23, 2017 at 01:38:38AM -0500, Kai-Heng Feng wrote:
>> r8153 on Dell TB dock corrupts rx packets.
>> 
>> The root cause is not found yet, but disabling rx checksumming can
>> workaround the issue. We can use this connection to decide if it's
>> a Dell TB dock:
>> Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
>> 
>> BugLink: https://bugs.launchpad.net/bugs/1729674
>> Cc: Mario Limonciello 
>> Signed-off-by: Kai-Heng Feng 
>> ---
>> drivers/net/usb/r8152.c | 33 -
>> 1 file changed, 32 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
>> index d51d9abf7986..58b80b5e7803 100644
>> --- a/drivers/net/usb/r8152.c
>> +++ b/drivers/net/usb/r8152.c
>> @@ -27,6 +27,8 @@
>> #include 
>> #include 
>> #include 
>> +#include 
>> +#include 
>> 
>> /* Information for net-next */
>> #define NETNEXT_VERSION  "09"
>> @@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface *intf)
>>  return version;
>> }
>> 
>> +/* Ethernet on Dell TB 15/16 dock is connected this way:
>> + * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
>> + * We use this connection to make sure r8153 is on the Dell TB dock.
>> + */
>> +static bool check_dell_tb_dock(struct usb_device *udev)
>> +{
>> +struct usb_device *hub = udev->parent;
>> +struct usb_device *root_hub;
>> +struct pci_dev *controller;
>> +
>> +if (!hub)
>> +return false;
>> +
>> +if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
>> +  le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
>> +return false;
>> +
>> +root_hub = hub->parent;
>> +if (!root_hub || root_hub->parent)
>> +return false;
>> +
>> +controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);
> 
> That's a very scary, and dangerous, cast.  You can not ever be sure that
> the hub really is a "root hub" like this.

What I want to do here is to finding this connection:
Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> 
ASMedia XHCI controller (PCI ID: 1b21:1142).

Is there a safer way to do this?

> 
>> +if (controller->vendor == 0x1b21 && controller->device == 0x1142)
>> +return true;
> 
> Why can't you just look at the USB device itself and go off of a quirk
> in it?  Something like a version or string or something else?

I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any 
information to differentiate them. Hence I want to use the connection to
identify if r8153 is on a Dell TB dock.

> 
> This sounds like a USB host controller issue, not a USB device issue,
> can't we fix the "real" problem here instead of this crazy work-around?

Yes. From what I know, ASMedia is working on it, but not sure how long it
will take. In the meantime, I’d like to workaround this issue for the users.

> Odds are any device plugged into the hub should have the same issue,
> right?

Actually no.
I just plugged r8153 dongle into the same hub, surprisingly the issue
doesn’t happen in this scenario.

Kai-Heng

> 
> thanks,
> 
> greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Thu, Nov 23, 2017 at 01:38:38AM -0500, Kai-Heng Feng wrote:
> r8153 on Dell TB dock corrupts rx packets.
> 
> The root cause is not found yet, but disabling rx checksumming can
> workaround the issue. We can use this connection to decide if it's
> a Dell TB dock:
> Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> 
> BugLink: https://bugs.launchpad.net/bugs/1729674
> Cc: Mario Limonciello 
> Signed-off-by: Kai-Heng Feng 
> ---
>  drivers/net/usb/r8152.c | 33 -
>  1 file changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index d51d9abf7986..58b80b5e7803 100644
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -27,6 +27,8 @@
>  #include 
>  #include 
>  #include 
> +#include 
> +#include 
>  
>  /* Information for net-next */
>  #define NETNEXT_VERSION  "09"
> @@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface *intf)
>   return version;
>  }
>  
> +/* Ethernet on Dell TB 15/16 dock is connected this way:
> + * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> + * We use this connection to make sure r8153 is on the Dell TB dock.
> + */
> +static bool check_dell_tb_dock(struct usb_device *udev)
> +{
> + struct usb_device *hub = udev->parent;
> + struct usb_device *root_hub;
> + struct pci_dev *controller;
> +
> + if (!hub)
> + return false;
> +
> + if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
> +   le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
> + return false;
> +
> + root_hub = hub->parent;
> + if (!root_hub || root_hub->parent)
> + return false;
> +
> + controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);

That's a very scary, and dangerous, cast.  You can not ever be sure that
the hub really is a "root hub" like this.

> + if (controller->vendor == 0x1b21 && controller->device == 0x1142)
> + return true;

Why can't you just look at the USB device itself and go off of a quirk
in it?  Something like a version or string or something else?

This sounds like a USB host controller issue, not a USB device issue,
can't we fix the "real" problem here instead of this crazy work-around?
Odds are any device plugged into the hub should have the same issue,
right?

thanks,

greg k-h

Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock

[Greg KH]

On Thu, Nov 23, 2017 at 01:38:38AM -0500, Kai-Heng Feng wrote:
> r8153 on Dell TB dock corrupts rx packets.
> 
> The root cause is not found yet, but disabling rx checksumming can
> workaround the issue. We can use this connection to decide if it's
> a Dell TB dock:
> Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> 
> BugLink: https://bugs.launchpad.net/bugs/1729674
> Cc: Mario Limonciello 
> Signed-off-by: Kai-Heng Feng 
> ---
>  drivers/net/usb/r8152.c | 33 -
>  1 file changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index d51d9abf7986..58b80b5e7803 100644
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -27,6 +27,8 @@
>  #include 
>  #include 
>  #include 
> +#include 
> +#include 
>  
>  /* Information for net-next */
>  #define NETNEXT_VERSION  "09"
> @@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface *intf)
>   return version;
>  }
>  
> +/* Ethernet on Dell TB 15/16 dock is connected this way:
> + * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
> + * We use this connection to make sure r8153 is on the Dell TB dock.
> + */
> +static bool check_dell_tb_dock(struct usb_device *udev)
> +{
> + struct usb_device *hub = udev->parent;
> + struct usb_device *root_hub;
> + struct pci_dev *controller;
> +
> + if (!hub)
> + return false;
> +
> + if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
> +   le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
> + return false;
> +
> + root_hub = hub->parent;
> + if (!root_hub || root_hub->parent)
> + return false;
> +
> + controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);

That's a very scary, and dangerous, cast.  You can not ever be sure that
the hub really is a "root hub" like this.

> + if (controller->vendor == 0x1b21 && controller->device == 0x1142)
> + return true;

Why can't you just look at the USB device itself and go off of a quirk
in it?  Something like a version or string or something else?

This sounds like a USB host controller issue, not a USB device issue,
can't we fix the "real" problem here instead of this crazy work-around?
Odds are any device plugged into the hub should have the same issue,
right?

thanks,

greg k-h

[PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai-Heng Feng]

r8153 on Dell TB dock corrupts rx packets.

The root cause is not found yet, but disabling rx checksumming can
workaround the issue. We can use this connection to decide if it's
a Dell TB dock:
Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller

BugLink: https://bugs.launchpad.net/bugs/1729674
Cc: Mario Limonciello 
Signed-off-by: Kai-Heng Feng 
---
 drivers/net/usb/r8152.c | 33 -
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index d51d9abf7986..58b80b5e7803 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -27,6 +27,8 @@
 #include 
 #include 
 #include 
+#include 
+#include 
 
 /* Information for net-next */
 #define NETNEXT_VERSION"09"
@@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface *intf)
return version;
 }
 
+/* Ethernet on Dell TB 15/16 dock is connected this way:
+ * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
+ * We use this connection to make sure r8153 is on the Dell TB dock.
+ */
+static bool check_dell_tb_dock(struct usb_device *udev)
+{
+   struct usb_device *hub = udev->parent;
+   struct usb_device *root_hub;
+   struct pci_dev *controller;
+
+   if (!hub)
+   return false;
+
+   if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
+ le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
+   return false;
+
+   root_hub = hub->parent;
+   if (!root_hub || root_hub->parent)
+   return false;
+
+   controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);
+
+   if (controller->vendor == 0x1b21 && controller->device == 0x1142)
+   return true;
+
+   return false;
+}
+
 static int rtl8152_probe(struct usb_interface *intf,
 const struct usb_device_id *id)
 {
@@ -5202,7 +5233,7 @@ static int rtl8152_probe(struct usb_interface *intf,
NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
NETIF_F_IPV6_CSUM | NETIF_F_TSO6;
 
-   if (tp->version == RTL_VER_01) {
+   if (tp->version == RTL_VER_01 || check_dell_tb_dock(udev)) {
netdev->features &= ~NETIF_F_RXCSUM;
netdev->hw_features &= ~NETIF_F_RXCSUM;
}
-- 
2.14.1

[PATCH] r8152: disable rx checksum offload on Dell TB dock

[Kai-Heng Feng]

r8153 on Dell TB dock corrupts rx packets.

The root cause is not found yet, but disabling rx checksumming can
workaround the issue. We can use this connection to decide if it's
a Dell TB dock:
Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller

BugLink: https://bugs.launchpad.net/bugs/1729674
Cc: Mario Limonciello 
Signed-off-by: Kai-Heng Feng 
---
 drivers/net/usb/r8152.c | 33 -
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index d51d9abf7986..58b80b5e7803 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -27,6 +27,8 @@
 #include 
 #include 
 #include 
+#include 
+#include 
 
 /* Information for net-next */
 #define NETNEXT_VERSION"09"
@@ -5135,6 +5137,35 @@ static u8 rtl_get_version(struct usb_interface *intf)
return version;
 }
 
+/* Ethernet on Dell TB 15/16 dock is connected this way:
+ * Realtek r8153 <-> SMSC hub <-> ASMedia XHCI controller
+ * We use this connection to make sure r8153 is on the Dell TB dock.
+ */
+static bool check_dell_tb_dock(struct usb_device *udev)
+{
+   struct usb_device *hub = udev->parent;
+   struct usb_device *root_hub;
+   struct pci_dev *controller;
+
+   if (!hub)
+   return false;
+
+   if (!(le16_to_cpu(hub->descriptor.idVendor) == 0x0424 &&
+ le16_to_cpu(hub->descriptor.idProduct) == 0x5537))
+   return false;
+
+   root_hub = hub->parent;
+   if (!root_hub || root_hub->parent)
+   return false;
+
+   controller = to_pci_dev(bus_to_hcd(root_hub->bus)->self.controller);
+
+   if (controller->vendor == 0x1b21 && controller->device == 0x1142)
+   return true;
+
+   return false;
+}
+
 static int rtl8152_probe(struct usb_interface *intf,
 const struct usb_device_id *id)
 {
@@ -5202,7 +5233,7 @@ static int rtl8152_probe(struct usb_interface *intf,
NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
NETIF_F_IPV6_CSUM | NETIF_F_TSO6;
 
-   if (tp->version == RTL_VER_01) {
+   if (tp->version == RTL_VER_01 || check_dell_tb_dock(udev)) {
netdev->features &= ~NETIF_F_RXCSUM;
netdev->hw_features &= ~NETIF_F_RXCSUM;
}
-- 
2.14.1