Re: [PATCH 0/1] Fixes to the USB 3.0 detection as 2.0 on AMD platform

[Gavin Guo]

Hi Greg,

On Sat, Jul 12, 2014 at 8:04 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Sat, Jul 12, 2014 at 07:32:34AM +0800, Gavin Guo wrote:
>> Hi all,
>>
>> On Fri, Jul 11, 2014 at 2:22 PM, Gavin Guo <gavin.guo@xxxxxxxxxxxxx> wrote:
>> > Hi Sarah and Mathias,
>> >
>> > As the discussion in http://comments.gmane.org/gmane.linux.usb.general/107011,
>> > I found that [AMD] FCH USB XHCI Controller [1022:7814] the USB 3.0 disk
>> > can't work in SuperSpeed after several times of hotplug. After doing some
>> > experiments and bisection, I found the bug is caused by
>> > 41e7e056cdc662f704fa9262e5c6e213b4ab45dd (USB: Allow USB 3.0 ports to be
>> > disabled.). And the bug can be fixed by not executing the
>> > hub_usb3_port_disable() function. I also found that the port status is
>> > already in RxDetect before setting the port to Disabled in
>> > hub_usb3_port_disable() function. So, there are 2 ways to fix the bug:
>> >
>> > 1) Check if the Vendor/Device id is [1022:7814] at the beginning of
>> > hub_usb3_port_disable() function. If yes, return without executing the
>> > remaining code.
>> >
>> > 2) Check if the port status is already in RxDetect, if yes, return without
>> > executing the remaining code.
>> >
>> > The second method seems more reasonable, so the patch is the implementation
>> > of the second one. But it will affect more platforms and I don't know if
>> > there'll be any negative result. Otherwise, if the first one is correct,
>> > I can reimplement a new one.
>> >
>> > I'm appreciated if you can give me some advice, or if there is any thing I missed.
>> >
>> > Thanks,
>> > Gavin
>> >
>> > Gavin Guo (1):
>> >   usb: Check if port status is equal to RxDetect
>> >
>> >  drivers/usb/core/hub.c | 19 +++++++++++++++++++
>> >  1 file changed, 19 insertions(+)
>> >
>> > --
>> > 2.0.0
>> >
>>
>> Add Greg k-h to the list.
>
> Why?  Mathias can handle this just fine, right?
>
> And I read all linux-usb@vger email anyway...
>
> greg k-h

I'm sorry if there is any misunderstanding. Because the code is under
drivers/usb/core/hub.c, I found that in MAINTAINERS you are the
maintainer of drivers/usb/*. so I think it's better to let you know
the change.

Thanks,
Gavin Guo
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