From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?RnJhbmsgU2Now6RmZXI=?= Subject: Re: Does USB isochronous mode work on EHCI port? Date: Fri, 04 Jan 2013 17:33:08 +0100 Message-ID: <50E70444.7090407@googlemail.com> References: <32bbff70-2fcd-4993-92ea-385ab02f735a@googlegroups.com> <6ffddeae-3f7b-4972-a485-c62ecc7e2cdb@googlegroups.com> <50E6D710.4060409@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50E6D710.4060409-l0cyMroinI0@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Gary Thomas Cc: rogerq-l0cyMroinI0@public.gmane.org, pandaboard-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, balbi-l0cyMroinI0@public.gmane.org, balbif-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-omap@vger.kernel.org Am 04.01.2013 14:20, schrieb Roger Quadros: > Hi Gary, > > On 01/04/2013 02:20 PM, Gary Thomas wrote: >> >> On Thursday, January 3, 2013 9:21:19 AM UTC-7, Felipe Balbi wrote: >> >> Hi, >> >> On Wednesday, January 2, 2013 10:44:50 PM UTC+2, Gary Thomas wrote: >> >> I have a video adapter attached to my EHCI port which runs full >> speed (480Mb/s) isochronous mode. Sadly, I never get any data >> from the device (it uses the EM28xx driver). >> This same device + driver works fine on my laptop and from what >> I can tell looking at the module debug, it's failing when >> waiting for the ISOC frame data to arrive. >> >> Should this work? I recall lots of discussion in the past about >> ISOC transfers not working on certain OMAP devices... >> >> >> which kernel are you using ? Have you tested mainline kernel ? >> >> >> I'm using the TI/Ubuntu kernel ( ti-ubuntu-3.4.0-1489.17) >> >> Using the mainline would be hard as there is a lot in this kernel that >> isn't in the mainline. I have added support for USB bulk transfers to the em28xx driver recently. It will be include in kernels 3.9+. Maybe it can be used to work around hardware problems with ISOC transfers. So if your device has bulk endpoints for video (see lsusb -v), it's probably worth testing the latest code from the media tree (http://git.linuxtv.org/media_tree.git). You will have to load the module with parameter usb_xfer_mode=1, otherwise the driver selects ISOC transfers for TV devices by default. Regards, Frank -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html