Re: [PATCH v2 3/7] usb: gadget: f_uvc: change endpoint allocation in uvc_function_bind()

[yuan linyu <cugyly@163.com>]

On 2023/12/20 00:17, Frank Li wrote:
> On Thu, Aug 03, 2023 at 05:10:49PM +0800, Linyu Yuan wrote:
>> when call uvc_function_bind(), gadget still have no connection speed,
>> just follow other gadget function, use fs endpoint descriptor to allocate
>> a video endpoint, remove gadget_is_{super|dual}speed() API call.
>>
>> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
>> ---
>> v2: no change
>>
>>  drivers/usb/gadget/function/f_uvc.c | 10 +---------
>>  1 file changed, 1 insertion(+), 9 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
>> index 5e919fb65833..c8e149f8315f 100644
>> --- a/drivers/usb/gadget/function/f_uvc.c
>> +++ b/drivers/usb/gadget/function/f_uvc.c
>> @@ -719,21 +719,13 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
>>  	}
>>  	uvc->enable_interrupt_ep = opts->enable_interrupt_ep;
>>  
>> -	if (gadget_is_superspeed(c->cdev->gadget))
>> -		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
>> -					  &uvc_ss_streaming_comp);
>> -	else if (gadget_is_dualspeed(cdev->gadget))
>> -		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
>> -	else
>> -		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
>> -
>> +	ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
> Some UDC driver use gadget_check_config() and match_ep() to allocate EP
> internal fifo memory resource, if only pass download full speed EP.
Could you share  the detail of problem ? do you mean find another different endpoint compared

with change before?


From my understanding, according to configfs gadget driver design, when find a endpoint, there is no

working speed, this means each hardware endpoint should support all possible speeds.
>
> UDC will allocate too much internal memory to each EP. It may failure when
> use ss config. Generally, ss config have bigger max package size.
is there another way to solve your issue in your driver ?
>
> Frank
>
>>  	if (!ep) {
>>  		uvcg_info(f, "Unable to allocate streaming EP\n");
>>  		goto error;
>>  	}
>>  	uvc->video.ep = ep;
>>  
>> -	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
>>  	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
>>  	uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address;
>>  
>> -- 
>> 2.17.1
>>