Re: [PATCH v12 6/9] usb: xhci: use bus->sysdev for DMA configuration

[Vivek Gautam]

On Thu, Feb 9, 2017 at 5:24 PM, Roger Quadros <rogerq@xxxxxx> wrote:
>
>
> On 09/02/17 13:53, Roger Quadros wrote:
>>
>>
>> On 08/02/17 22:43, Jack Pham wrote:
>>> Hi Peter, Sriram, Arnd,
>>>
>>> On Mon, Feb 06, 2017 at 05:13:38PM +0800, Peter Chen wrote:
>>>> From: Arnd Bergmann <arnd@xxxxxxxx>
>>>>
>>>> For xhci-hcd platform device, all the DMA parameters are not
>>>> configured properly, notably dma ops for dwc3 devices. So, set
>>>> the dma for xhci from sysdev. sysdev is pointing to device that
>>>> is known to the system firmware or hardware.
>>>>
>>>> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>>>> Signed-off-by: Sriram Dash <sriram.dash@xxxxxxx>
>>>> Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>>>> Tested-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
>>>> Tested-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
>>>> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
>>>> ---
>>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
>>>> index 6d33b42..7a9c860 100644
>>>> --- a/drivers/usb/host/xhci-plat.c
>>>> +++ b/drivers/usb/host/xhci-plat.c
>>>
>>>> -   hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
>>>> +   hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
>>>> +                          dev_name(&pdev->dev), NULL);
>>>
>>> As mentioned already in [1], usb_create_shared_hcd() is called to create
>>> the second bus, however it also needs to be converted.
>>>
>>> Not exactly as Roger's suggestion but this worked for me:
>>>
>>> -       xhci->shared_hcd = usb_create_shared_hcd(driver, &pdev->dev,
>>> +       xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
>>>                         dev_name(&pdev->dev), hcd);
>>
>> But we're creating a shared_hcd and there is an API for that so why not use it
>> instead of calling __usb_create_hcd()?
>>
>
> Just realized after I pressed send that there is no sysdev parameter
> for create_shared_hcd().

That's right. The create_shared_hcd() makes use of only pdev->dev,
and we need to configure dma for shared_hcd as well though sysdev.

Sorry my mail client didn't show this mail in time. Please ignore my
earlier comment.

>
>>>         if (!xhci->shared_hcd) {
>>>                 ret = -ENOMEM;
>>>
>>> Without this, SuperSpeed devices fail to enumerate:
>>>
>>>  usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
>>>  usb 2-1: device descriptor read/8, error -11
>>>  usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
>>>  usb 2-1: device descriptor read/8, error -11
>>>  usb 2-1: new SuperSpeed USB device number 3 using xhci-hcd
>>>  usb 2-1: device descriptor read/8, error -11
>>>  usb 2-1: new SuperSpeed USB device number 3 using xhci-hcd
>>>  usb 2-1: device descriptor read/8, error -11
>>>  <and continues...>
>>>
>>> Thanks,
>>> Jack
>>>
>>> [1] https://lkml.org/lkml/2016/12/9/240
>>>
>>
>
> --
> cheers,
> -roger
> --
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