[U-Boot] [xHCI] Controller failure with USB 3.0 hub

[Bin Meng]

Hi Marek,

On Sat, May 19, 2018 at 7:30 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
> On 05/19/2018 01:09 PM, Bin Meng wrote:
>> Hi Marek,
>
> Hi,
>
>> On Sat, May 19, 2018 at 9:03 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
>>> Hello Bin,
>>>
>>> I noticed a potential bug in the U-Boot xHCI implementation. I observe
>>> this one Renesas RCar Gen3 platform.
>>>
>>> If I plug a USB 3.0 hub into the root port, I see the following error:
>>>   ERROR: Configure Endpoint command returned completion code 5.
>>> If I plug a USB 3.0 stick into the root port, I do not get the error and
>>> the stick is correctly detected.
>>>
>>> Example with the USB 3.0 hub:
>>>
>>> => usb reset
>>> resetting USB...
>>> USB0:   Register 2000120 NbrPorts 2
>>> Starting the controller
>>> USB XHCI 1.00
>>> USB1:   USB EHCI 1.10
>>> USB2:   USB EHCI 1.10
>>> USB3:   USB EHCI 1.10
>>> ******** HERE ********
>>> scanning bus 0 for devices... ERROR: Configure Endpoint command returned
>>> completion code 5.
>>
>> Completion code 5 means TRB parameter error, guess the Renesas xHC has
>> some checks on the TRB.
>
> Do you have xhci spec chapter reference/number for me too ? :)
>

I was looking at xhci spec 1.1 chapter 6.4.5 TRB Completion Codes. I
don't have Renesas xHC manual to cross check.

>> Can you try the following patch to see if it makes any difference?
>>
>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>> index 3adb002..eec3f64 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -1453,6 +1453,8 @@ static int xhci_update_hub_device(struct udevice
>> *dev, struct usb_device *udev)
>>         if (udev->speed == USB_SPEED_HIGH)
>>                 slot_ctx->tt_info |= cpu_to_le32(TT_THINK_TIME(think_time));
>>
>> +       slot_ctx->dev_state = 0;
>> +
>>         return xhci_configure_endpoints(udev, false);
>>  }
>
> Doesn't make any difference, sorry.
>

Too bad. Then I don't have any obvious clue so far. The completion
code 5 is a helpful sign from xHC to the software that something was
wrong in the TRB. Per the xHCI spec, dev_state needs to be cleared. It
was working with the x86 xHC though. Changing
xhci_configure_endpoints(udev, false) to
xhci_configure_endpoints(udev, true) is not correct as the Evaluate
Context command is not used with configure the hub attributes.

Regards,
Bin