Re: testusb: epipe errors on test 9 and 10

[Angelo Dureghello <angelo@kernel-space.org>]

Hi Alan,

On 12/4/25 23:26, Alan Stern wrote:
> On Tue, Dec 02, 2025 at 11:22:38PM +0000, Thinh Nguyen wrote:
>> On Tue, Dec 02, 2025, Alan Stern wrote:
>>> On Tue, Dec 02, 2025 at 04:23:13AM +0000, Thinh Nguyen wrote:
>>>> On Mon, Dec 01, 2025, Alan Stern wrote:
>>>>> Are we talking about the same thing?  Clear-Feature is different from
>>>>> Get-Interface-Status.
>>>>>
>>>> Ah... I just saw the subject line testusb -EPIPE and assumed that it's
>>>> related to ClearFeature(halt_ep)..
>>>>
>>>> The Get-Interface-Status should be hand-off and handled by gzero right?
>>>> The gadget driver knows about the status of the interface, not UDC
>>>> driver.
>>> For USB-2 devices, Get-Interface-Status is always supposed to return two
>>> bytes of 0.  For USB-3 devices, it returns information about Function
>>> Remote Wakeup and Function Remote Wakeup Capable, which is handled
>>> already by the composite core.
>>>
>>> So for SuperSpeed and above, the request should be delegated.  For high
>>> speed and below, it could be done either way.  (dummy-hcd makes the
>>> opposite mistake; it always returns zeros for Get-Interface-Status and
>>> never delegates.)
>>>
>>> If you think it's best always to delegate the request then composite.c
>>> needs to be changed; it should handle the reply for non-SuperSpeed
>>> connections.  A simple change; I can do it.  What do you prefer?
>>>
>> Right this change is simple. I think it's probably easier to delegate
>> and enforce this in the composite library instead of auditing all the
>> UDC drivers.
> Here's a patch to try.  Angelo, can you test this?
>
> Alan Stern
>
>
>
> Index: usb-devel/drivers/usb/gadget/composite.c
> ===================================================================
> --- usb-devel.orig/drivers/usb/gadget/composite.c
> +++ usb-devel/drivers/usb/gadget/composite.c
> @@ -1966,25 +1966,27 @@ composite_setup(struct usb_gadget *gadge
>   			break;
>   		}
>   
> -		/*
> -		 * USB 3.0 additions:
> -		 * Function driver should handle get_status request. If such cb
> -		 * wasn't supplied we respond with default value = 0
> -		 * Note: function driver should supply such cb only for the
> -		 * first interface of the function
> -		 */
> -		if (!gadget_is_superspeed(gadget))
> -			goto unknown;
> +		/* UDC driver should handle device and endpoint recipients */
>   		if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
>   			goto unknown;
> -		value = 2;	/* This is the length of the get_status reply */
> -		put_unaligned_le16(0, req->buf);
>   		if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
>   			break;
>   		f = cdev->config->interface[intf];
>   		if (!f)
>   			break;
>   
> +		value = 2;	/* This is the length of the get_status reply */
> +		put_unaligned_le16(0, req->buf);
> +		if (!gadget_is_superspeed(gadget))
> +			break;	/* USB-2 always returns zeros */
> +
> +		/*
> +		 * USB 3.0 additions:
> +		 * Function driver should handle get_status request. If such cb
> +		 * wasn't supplied we respond with default value = 0
> +		 * Note: function driver should supply such cb only for the
> +		 * first interface of the function
> +		 */
>   		if (f->get_status) {
>   			status = f->get_status(f);
>   
thanks a lot.

I am actually stuck working in 5-4 kernel, where the issue was detected, 
but will do my best to test this
as soon as i can .

Regards,
angelo