From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from galahad.ideasonboard.com ([185.26.127.97]:56954 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751643AbcIZQGb (ORCPT ); Mon, 26 Sep 2016 12:06:31 -0400 From: Laurent Pinchart To: Felipe Balbi Cc: yfw , Bin Liu , linux-usb@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: g_webcam Isoch high bandwidth transfer Date: Mon, 26 Sep 2016 19:06:23 +0300 Message-ID: <1685763.WH6ULF9Rxs@avalon> In-Reply-To: <87k2e358cx.fsf@linux.intel.com> References: <20160920170441.GA10705@uda0271908> <87k2e358cx.fsf@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Felipe, On Friday 23 Sep 2016 11:27:26 Felipe Balbi wrote: > yfw writes: > >>>>>> Here's one that actually compiles, sorry about that. > >>>>> > >>>>> No worries, I was sleeping ;-) > >>>>> > >>>>> I will test it out early next week. Thanks. > >>>> > >>>> meanwhile, how about some instructions on how to test this out myself? > >>>> How are you using g_webcam and what are you running on host side? Got a > >>>> nice list of commands there I can use? I think I can get to bottom of > >>>> this much quicker if I can reproduce it locally ;-) > >>> > >>> On device side: > >>> - first patch g_webcam as in my first email in this thread to enable > >>> 640x480@30fps; > >>> - # modprobe g_webcam streaming_maxpacket=3072 > >>> - then run uvc-gadget to feed the YUV frames; > >>> http://git.ideasonboard.org/uvc-gadget.git > >> > >> as is, g_webcam never enumerates to the host. It's calls to > >> usb_function_active() and usb_function_deactivate() are unbalanced. Do > >> you have any other changes to g_webcam? > > > > With uvc function gadget driver, user daemon uvc-gadget must be started > > before connect to host. Not sure whether g_webcam has same requirement. > > f_uvc.c should be handling that by means for usb_function_deactivate(). > > I'll try keeping cable disconnected until uvc-gadget is running. Things might have changed since we've discussed the issue several years ago, but back then at least the musb UDC started unconditionally connected. -- Regards, Laurent Pinchart