From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Subject: Re: [PATCH] drm/edid: Add both 60Hz and 59.94Hz CEA modes to connector's mode list Date: Fri, 31 May 2013 19:56:30 +0100 Message-ID: <51A8F25E.3060102@gmail.com> References: <1370003021-16594-1-git-send-email-ville.syrjala@linux.intel.com> <20130531154351.GY15743@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail-ea0-f181.google.com (mail-ea0-f181.google.com [209.85.215.181]) by gabe.freedesktop.org (Postfix) with ESMTP id 23B8FE5CE2 for ; Fri, 31 May 2013 11:56:34 -0700 (PDT) Received: by mail-ea0-f181.google.com with SMTP id a11so1978157eae.26 for ; Fri, 31 May 2013 11:56:33 -0700 (PDT) In-Reply-To: <20130531154351.GY15743@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Daniel Vetter Cc: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org Daniel Vetter wrote: > On Fri, May 31, 2013 at 03:23:41PM +0300, ville.syrjala@linux.intel.com w= rote: >> From: Ville Syrj=E4l=E4 >> >> Having both modes can be beneficial for video playback cases. If you can >> match the video framerate exactly, and the audio and video clocks come >> from the same source, you should be able to avoid dropped/repeated >> frames without expensive operations such as resampling the audio to >> match video output rate. >> >> Rather than add both variants based on the CEA extension short video >> descriptors in do_cea_modes(), add only one variant there. Once all >> the EDID has been fully probed, do a loop over the entire probed mode >> list, during which we add the other variants for all modes that match >> CEA modes. This allows us to match modes that didn't come via the CEA >> short video descriptors. For example one Samsung TV here doesn't have >> the 640x480-60 mode as a SVD, but instead it's specified via a detailed >> timing descriptor. >> >> Signed-off-by: Ville Syrj=E4l=E4 >> --- >> A few people requested this. Originally I was a bit opposed to it, but >> when I thought about it a bit more I figured if the audio and video >> clocks come from the same source (or happen to be close enough w/o >> significant drift), this could provide a better A/V sync w/o resampling >> tricks. > > Yeah, I think this should be useful for a bunch of people. I've recently > chatted with a few xbmc folks on #irc and one thing they've requested is > mode fine-tuning. For DP we should have plenty of precision, but for HDMI > we'd need to (slightly) frob the vtotal ever so often to compensate. With > some runtime-tuning a la npt we should have perfect a/v sync without any > audio resampling. Apologies, for jumping in here, but assuming I haven't missed anything = you've done already: do you have any plans for supporting CEA interlaced = modes? That's assuming they actually need any more support - I only know that = they are slightly wrong for me testing with radeon + my TV - are they = tested and known to work / not work on intel hw? The symptom I get is not instantly obvious - the second half of the = bottom line gets rendered and repeated as the top line. For me the reason that proper support could in theory be useful, is that = were there in future a way to sync up properly, my TV will do a nice = "free" deinterlace. Even on a fast quad core PC doing one as good on cpu = is not possible for HD 50i.