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

[Jack Pham]

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);
        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
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