Hi,
On 07/12/2016 09:48 AM, Lipengcheng wrote:
> Hi,
>
>> -----Original Message-----
>> From: Lu Baolu [mailto:baolu...@linux.intel.com]
>> Sent: Tuesday, July 12, 2016 8:42 AM
>> To: Lipengcheng; gre...@linuxfoundation.org; st...@rowland.harvard.edu;
>> chasemetzge...@gmail.com; mathias.ny...@linux.intel.com;
>> oneu...@suse.com; jun...@freescale.com
>> Cc: linux-...@vger.kernel.org; linux-kernel@vger.kernel.org
>> Subject: Re: [PATCH] usb:solve resume usb device identification problem
>>
>> Hi,
>>
>> On 07/11/2016 08:57 PM, Pengcheng Li wrote:
>>> A usb device in the connection state. Then host is suspend and resume.
>>> But the usb device could not be at the right speed. We should be reset
>>> the reset.
>> Have you tried applying XHCI_RESET_ON_RESUME quirk to your host controller
>> driver? Is your usb device self powered?
>>
> I do not apply XHCI_RESET_ON_RESUME quir to my host controller driver. I
> select no pci platform. Our usb device is not self powered.
This quirk is not pci specific.
>> Best regards,
>> Lu Baolu
>>
>>> Signed-off-by: Pengcheng Li <lpc...@hisilicon.com>
>>> ---
>>> drivers/usb/core/hub.c | 6 +++++-
>>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index
>>> bee1351..cd71bb3 100644
>>> --- a/drivers/usb/core/hub.c
>>> +++ b/drivers/usb/core/hub.c
>>> @@ -3455,7 +3455,7 @@ int usb_port_resume(struct usb_device *udev,
>>> pm_message_t msg)
>>> struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
>>> struct usb_port *port_dev = hub->ports[udev->portnum - 1];
>>> int port1 = udev->portnum;
>>> - int status;
>>> + int status, retval;
>>> u16 portchange, portstatus;
>>>
>>> if (!test_and_set_bit(port1, hub->child_usage_bits)) { @@ -3512,6
>>> +3512,10 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
>>> }
>>> }
>>>
>>> + retval = hub_port_reset(hub, port1, udev, HUB_ROOT_RESET_TIME, false);
>>> + if (retval < 0)
>>> + hub_port_disable(hub, port1, 0);
>>> +
If I understand it right, this is a "host + device" specific issue. This line
of code
might solve your issue, but it impacts all other hosts and devices which don't
have such problem.
Best regards,
Lu Baolu
