Re: [PATCH 1/3] usb: gadget: uvc: Rename uvc_control_ep

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Dan,

Thank you for the patch.

On Mon, Dec 05, 2022 at 02:37:56PM +0000, Daniel Scally wrote:
> The f_uvc code defines an endpoint named "uvc_control_ep" but it
> is configured with a non-zero endpoint address and has its
> bmAttributes flagged as USB_ENDPOINT_XFER_INT - this cannot be the
> VideoControl interface's control endpoint, as the default endpoint
> 0 is used for that purpose. This is instead the optional interrupt
> endpoint that can be contained by a VideoControl interface.
> 
> Rename the variables to make that clear.
> 
> Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
> ---
>  drivers/usb/gadget/function/f_uvc.c | 24 ++++++++++++------------
>  drivers/usb/gadget/function/uvc.h   |  2 +-
>  2 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
> index 6e196e06181e..49b7231742d6 100644
> --- a/drivers/usb/gadget/function/f_uvc.c
> +++ b/drivers/usb/gadget/function/f_uvc.c
> @@ -86,7 +86,7 @@ static struct usb_interface_descriptor uvc_control_intf = {
>  	.iInterface		= 0,
>  };
>  
> -static struct usb_endpoint_descriptor uvc_control_ep = {
> +static struct usb_endpoint_descriptor uvc_interrupt_ep = {
>  	.bLength		= USB_DT_ENDPOINT_SIZE,
>  	.bDescriptorType	= USB_DT_ENDPOINT,
>  	.bEndpointAddress	= USB_DIR_IN,
> @@ -290,14 +290,14 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
>  		if (alt)
>  			return -EINVAL;
>  
> -		uvcg_info(f, "reset UVC Control\n");
> -		usb_ep_disable(uvc->control_ep);
> +		uvcg_info(f, "reset UVC interrupt endpoint\n");
> +		usb_ep_disable(uvc->interrupt_ep);

Technically it's called the "VideoControl Interrupt Endpoint", but that
would be quite long, and given that UVC has a single interrupt endpoint
in all interfaces, I think the name is fine.

>  
> -		if (!uvc->control_ep->desc)
> -			if (config_ep_by_speed(cdev->gadget, f, uvc->control_ep))
> +		if (!uvc->interrupt_ep->desc)
> +			if (config_ep_by_speed(cdev->gadget, f, uvc->interrupt_ep))
>  				return -EINVAL;
>  
> -		usb_ep_enable(uvc->control_ep);
> +		usb_ep_enable(uvc->interrupt_ep);
>  
>  		if (uvc->state == UVC_STATE_DISCONNECTED) {
>  			memset(&v4l2_event, 0, sizeof(v4l2_event));
> @@ -375,7 +375,7 @@ uvc_function_disable(struct usb_function *f)
>  	uvc->state = UVC_STATE_DISCONNECTED;
>  
>  	usb_ep_disable(uvc->video.ep);
> -	usb_ep_disable(uvc->control_ep);
> +	usb_ep_disable(uvc->interrupt_ep);
>  }
>  
>  /* --------------------------------------------------------------------------
> @@ -511,7 +511,7 @@ uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
>  	 * uvc_iad
>  	 * uvc_control_intf
>  	 * Class-specific UVC control descriptors
> -	 * uvc_control_ep
> +	 * uvc_interrupt_ep
>  	 * uvc_control_cs_ep
>  	 * uvc_ss_control_comp (for SS only)

Shouldn't you also rename those two variables ?

Ideally I would also rename struct uvc_control_endpoint_descriptor and
UVC_DT_CONTROL_ENDPOINT_SIZE, but those are exposed to userspace :-(

>  	 * uvc_streaming_intf_alt0
> @@ -523,7 +523,7 @@ uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
>  	control_size = 0;
>  	streaming_size = 0;
>  	bytes = uvc_iad.bLength + uvc_control_intf.bLength
> -	      + uvc_control_ep.bLength + uvc_control_cs_ep.bLength
> +	      + uvc_interrupt_ep.bLength + uvc_control_cs_ep.bLength
>  	      + uvc_streaming_intf_alt0.bLength;
>  
>  	if (speed == USB_SPEED_SUPER) {
> @@ -569,7 +569,7 @@ uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
>  	uvc_control_header->bInCollection = 1;
>  	uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
>  
> -	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
> +	UVC_COPY_DESCRIPTOR(mem, dst, &uvc_interrupt_ep);
>  	if (speed == USB_SPEED_SUPER)
>  		UVC_COPY_DESCRIPTOR(mem, dst, &uvc_ss_control_comp);
>  
> @@ -656,12 +656,12 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
>  			    (opts->streaming_maxburst + 1));
>  
>  	/* Allocate endpoints. */
> -	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
> +	ep = usb_ep_autoconfig(cdev->gadget, &uvc_interrupt_ep);
>  	if (!ep) {
>  		uvcg_info(f, "Unable to allocate control EP\n");
>  		goto error;
>  	}
> -	uvc->control_ep = ep;
> +	uvc->interrupt_ep = ep;
>  
>  	if (gadget_is_superspeed(c->cdev->gadget))
>  		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
> diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
> index 40226b1f7e14..48b71e04c2b1 100644
> --- a/drivers/usb/gadget/function/uvc.h
> +++ b/drivers/usb/gadget/function/uvc.h
> @@ -146,7 +146,7 @@ struct uvc_device {
>  	} desc;
>  
>  	unsigned int control_intf;
> -	struct usb_ep *control_ep;
> +	struct usb_ep *interrupt_ep;
>  	struct usb_request *control_req;
>  	void *control_buf;
>  

-- 
Regards,

Laurent Pinchart