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:

quoted

From: Arnd Bergmann <arnd@arndb.de>

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@arndb.de>
Signed-off-by: Sriram Dash <redacted>
Tested-by: Baolin Wang <redacted>
Tested-by: Vivek Gautam <redacted>
Tested-by: Alexander Sverdlin <redacted>
Signed-off-by: Mathias Nyman <redacted>
---

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

quoted

-	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()?

        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