Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> writes: > On Tue, Oct 05, 2021 at 02:53:48AM +0300, Laurent Pinchart wrote: >> Hi Michael, >> >> Thank you for resending this. >> >> On Sun, Oct 03, 2021 at 10:13:55PM +0200, Michael Grzeschik wrote: >> > From: Thomas Haemmerle <thomas.haemmerle@xxxxxxxxxxxxxx> >> > >> > Currently, the UVC function is activated when open on the corresponding >> > v4l2 device is called. >> > On another open the activation of the function fails since the >> > deactivation counter in `usb_function_activate` equals 0. However the >> > error is not returned to userspace since the open of the v4l2 device is >> > successful. >> > >> > On a close the function is deactivated (since deactivation counter still >> > equals 0) and the video is disabled in `uvc_v4l2_release`, although the >> > UVC application potentially is streaming. >> > >> > Move activation of UVC function to subscription on UVC_EVENT_SETUP >> > because there we can guarantee for a userspace application utilizing >> > UVC. >> > Block subscription on UVC_EVENT_SETUP while another application already >> > is subscribed to it, indicated by `bool func_connected` in >> > `struct uvc_device`. >> > Extend the `struct uvc_file_handle` with member `bool is_uvc_app_handle` >> > to tag it as the handle used by the userspace UVC application. >> >> Reflowing the paragraph would be nice (this could be done when applying >> the patch, or not at all). >> >> > With this a process is able to check capabilities of the v4l2 device >> > without deactivating the function for the actual UVC application. >> > >> > Reviewed-By: Michael Tretter <m.tretter@xxxxxxxxxxxxxx> >> > Signed-off-by: Thomas Haemmerle <thomas.haemmerle@xxxxxxxxxxxxxx> >> > Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx> >> > Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx> >> >> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> >> >> Felipe, please let me know if you want me to take this in my tree and >> issue a pull request, otherwise I'll assume you'll pick it up. > > I'll pick it up now, thanks. I guess it's too late for an Ack. FWIW: Acked-by: Felipe Balbi <balbi@xxxxxxxxxx> -- balbi
