RE: [PATCH] usb: host: xhci-plat: Iterate over parent nodes for finding quirks

[Anurag Kumar Vulisha]

Hi Greg,

>-----Original Message-----
>From: Greg Kroah-Hartman [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
>Sent: Tuesday, June 05, 2018 8:55 PM
>To: Anurag Kumar Vulisha <anuragku@xxxxxxxxxx>
>Cc: Mathias Nyman <mathias.nyman@xxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; linux-
>kernel@xxxxxxxxxxxxxxx
>Subject: Re: [PATCH] usb: host: xhci-plat: Iterate over parent nodes for finding quirks
>
>On Tue, Jun 05, 2018 at 08:50:56PM +0530, Anurag Kumar Vulisha wrote:
>> In xhci_plat_probe() both sysdev and pdev->dev are being used for
>> finding quirks. There are some drivers(like dwc3 host.c) which adds
>> quirks(like usb3-lpm-capable) into pdev and the logic present in
>> xhci_plat_probe() checks for quirks in either sysdev or pdev for
>> finding the quirks. Because of this logic, some of the quirks are
>> getting missed(usb3-lpm-capable quirk added by dwc3 host.c driver is
>> getting missed).This patch fixes this by iterating over all the
>> available parents for finding the quirks. In this way all the quirks
>> which are present in child or parent are correctly updated.
>>
>> Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xxxxxxxxxx>
>
>So this is a bugfix?  If so, how far back in the kernel releases should it go to?
>
I feel this is as a bugfix. This problem started with this patch
"usb: xhci: use bus->sysdev for DMA configuration (4c39d4b949d36faf)"
where pdev->dev is replaced with sysdev. If I am not wrong this bug is
present since 4.12 kernel release.

Thanks,
Anurag kumar Vulisha

>thanks,
>
>greg k-h