RE: [PATCH] usb: cdns3: Fixed incorrect gadget state

From: Pawel Laszczak
Date: Sun Jun 27 2021 - 23:46:52 EST


>
>On 21-06-23 09:02:47, Pawel Laszczak wrote:
>> From: Pawel Laszczak <pawell@xxxxxxxxxxx>
>>
>> For delayed status phase, the usb_gadget->state was set
>> to USB_STATE_ADDRESS and it has never been updated to
>> USB_STATE_CONFIGURED.
>> Patch updates the gadget state to correct USB_STATE_CONFIGURED.
>> As a result of this bug the controller was not able to enter to
>> Test Mode while using MSC function.
>
>Pawel, would you please describe more about this issue? I remember the cdns3
>controller at i.mx series SoC could enter test mode by using current
>code.

The issue occurs only for MSC class. MSC class has delayed status stage, so
after returning from cdns3_req_ep0_set_configuration function called
for Set Configuration driver remains in USB_STATE_ADDRESS.

In order to enter to test mode driver needs meet the condition included in
cdns3_ep0_feature_handle_device function:
if (state != USB_STATE_CONFIGURED || speed > USB_SPEED_HIGH)
return -EINVAL;

But it is still in USB_STATE_ADDRESS, because there was delayed status stage.
To fix issue driver state must be updated to USB_STATE_CONFIGURED before
or after finishing status stage.

>
>>
>> Cc: <stable@xxxxxxxxxxxxxxx>
>> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
>> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>> ---
>> drivers/usb/cdns3/cdns3-ep0.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/usb/cdns3/cdns3-ep0.c b/drivers/usb/cdns3/cdns3-ep0.c
>> index 9a17802275d5..ec5bfd8944c3 100644
>> --- a/drivers/usb/cdns3/cdns3-ep0.c
>> +++ b/drivers/usb/cdns3/cdns3-ep0.c
>> @@ -731,6 +731,7 @@ static int cdns3_gadget_ep0_queue(struct usb_ep *ep,
>> request->actual = 0;
>> priv_dev->status_completion_no_call = true;
>> priv_dev->pending_status_request = request;
>> + usb_gadget_set_state(&priv_dev->gadget, USB_STATE_CONFIGURED);
>> spin_unlock_irqrestore(&priv_dev->lock, flags);
>>
>> /*
>> --
>> 2.25.1
>>
>
--

Thanks,
Pawel Laszczak