Re: [PATCH v2 1/1] usb: xhci: fix return value of xhci_setup_device()

[Lu Baolu]

Hi Greg,

On 09/08/2016 04:58 PM, Greg KH wrote:
> On Thu, Sep 08, 2016 at 03:29:25PM +0800, Lu Baolu wrote:
>> Hi Greg,
>>
>> On 09/08/2016 02:38 PM, Greg KH wrote:
>>> On Thu, Sep 08, 2016 at 08:41:02AM +0800, Lu Baolu wrote:
>>>> xhci_setup_device() should return failure with correct error number
>>>> when xhci host has died, removed or halted.
>>>>
>>>> Cc: stable@xxxxxxxxxxxxxxx # 4.3+
>>> Why is this a stable kernel issue?  What bug does it fix that affects
>>> users?
>> During usb device enumeration, if xhci host is not accessible (died,
>> removed or halted), the hc_driver->address_device() should return
>> a corresponding error code to usb core. But current xhci driver just
>> returns success. This will mislead usb core to continue enumeration:
>> reading device descriptor, which will result in failure, and users will
>> get a misleading message like "device descriptor read/8, error -110".
> Why didn't you include this in the changelog text so that it is obvious
> why this patch is needed?
>
> Don't just describe what the patch does, we can read C code, describe
> _why_ it is needed.

Yes. Thank you for the guidance. I will do it in a v3 patch.

Best regards,
Lu Baolu