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 <mario.limoncie...@dell.com> > Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com> > --- > 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 <linux/usb/cdc.h> > #include <linux/suspend.h> > #include <linux/acpi.h> > +#include <linux/pci.h> > +#include <linux/usb/hcd.h> > > /* 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
