[U-Boot] [PATCH 05/20] usb: hub: Update handling connect status/change in usb_scan_port()

[Dinh Nguyen <dinguyen@kernel.org>]

On 06/16/2017 09:19 AM, Marek Vasut wrote:
> On 06/16/2017 03:31 PM, Bin Meng wrote:
>> It was observed that on Intel MinnowMax board, when xHCI is enabled
>> in the BayTrail SoC, with a USB 3.0 device connected to the bottom
>> USB 3.0 port (mapped to xHCI root port #7), its PORTSC register is
>> always 0x201203 (CCS = 1, CSC = 0). The root cause of such behavior
>> is unknown yet. Connect status change bit is set on the same port
>> with a USB 2.0 device (mapped to xHCI port #1, which is a different
>> port on the root hub).
>>
>> With current logic in usb_scan_port(), the enumeration process will
>> abort if it does not detect a connect status change on a hub port.
>> However since a device connection status is correctly reported, the
>> enumeration process can still continue.
>>
>> With this change, USB device connected to the bottom blue port on
>> MinnowMax board can be enumerated under either SS or HS mode.
>>
>> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
> 
> I'd be slightly concerned this can break some other controllers, like
> the DWC2 . CCing Dinh, maybe he can test it on SoCFPGA.
> 

I tested this patch on a SoCFPGA Atlas/DE0-Nano board, and USB is still
working fine.

Feel free to add:

Tested-by: Dinh Nguyen <dinguyen@kernel.org>