| Message ID | 20230803091053.9714-4-quic_linyyuan@quicinc.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | remove some usage of gadget_is_{*}speed() API | expand |
On 2023/12/21 00:02, Frank Li wrote: >>> 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 > The problem is little bit complex. I try to use simple words. > > The background: > > Generally, UDC have some EP<0..15> and have some internal memory as FIFO. > for example 16K. You can simple assign EP<n> to 1K memory, which can hold > whole package. > > But for UVC, some controller required internal FIFO hold whole frame data > > (mult+1) * (MaxBurst +1) * wPackageSize. > > For most case, not every gadget use all 16 EPs. So you can assgin more > memory into one EP, so it will reduce bus 'ping' package number and reduce > NACK to improve transfer speed. > > The problem: > pass fs_stream to udc driver, udc driver's check_config function will see > mult and maxburst is 0. so only reserve 1K for ISO EP, but when try to > enable EP, mult is 2, so there are not enough internal memory for it > because more memory already assign to other EPs. > > Ideally, when gadget frame work can call check_config again when know > usb speed, but it is not easy to fix it. > > Simple method use ss_stream_ep here and other function drviers. Super > speed's package size is bigger than high/full speed. If resource can > support super speed, it can support high/full speed. I don't find any difference of uvc_ss_streaming_ep, uvc_hs_streaming_ep, uvc_fs_streaming_ep descriptors. how difference happen in UDC ? > > > /** > * gadget_is_superspeed() - return true if the hardware handles superspeed > * @g: controller that might support superspeed > */ > > @max_speed: Highest speed the driver handles > > And according to gadget_is_superspeed() define, it indicate if udc > controller support supersped, not link speed. > > Orignial code is correct. If UDC support superspeed, then use ss_stream_ep. > > becasue superspeed is worse case compared as high and full speed. > > So I think original is correct. > > Frank. > >
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); 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;
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(-)