From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anssi Hannula Subject: Re: [PATCH 1/2] drm/radeon/audio: write audio/video latency info for DCE4/5 Date: Fri, 08 Nov 2013 13:24:46 +0200 Message-ID: <527CC9FE.6080902@iki.fi> References: <1382128919-29931-1-git-send-email-alexander.deucher@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sirokuusama.dnainternet.net (sirokuusama.dnainternet.net [83.102.40.133]) by gabe.freedesktop.org (Postfix) with ESMTP id AC48F1134BF for ; Fri, 8 Nov 2013 03:24:53 -0800 (PST) In-Reply-To: <1382128919-29931-1-git-send-email-alexander.deucher@amd.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org To: Alex Deucher , dri-devel@lists.freedesktop.org Cc: Alex Deucher List-Id: dri-devel@lists.freedesktop.org 18.10.2013 23:41, Alex Deucher kirjoitti: > Needed by the hda driver to properly set up synchronization > on the audio side. > > Signed-off-by: Alex Deucher > --- > drivers/gpu/drm/radeon/evergreen_hdmi.c | 37 ++++++++++++++++++++++++++++++++ > drivers/gpu/drm/radeon/evergreend.h | 38 +++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+) > > diff --git a/drivers/gpu/drm/radeon/evergreen_hdmi.c b/drivers/gpu/drm/radeon/evergreen_hdmi.c > index 5fbe486..abdc893 100644 > --- a/drivers/gpu/drm/radeon/evergreen_hdmi.c > +++ b/drivers/gpu/drm/radeon/evergreen_hdmi.c [...] > + if (connector->latency_present[0]) > + tmp = VIDEO_LIPSYNC(connector->video_latency[0]) | > + AUDIO_LIPSYNC(connector->audio_latency[0]); > + else > + tmp = VIDEO_LIPSYNC(255) | AUDIO_LIPSYNC(255); > + } > + WREG32(AZ_F0_CODEC_PIN0_CONTROL_RESPONSE_LIPSYNC, tmp); [...] > +#define AZ_F0_CODEC_PIN0_CONTROL_RESPONSE_LIPSYNC 0x5fe8 > +# define VIDEO_LIPSYNC(x) (((x) & 0xff) << 0) > +# define AUDIO_LIPSYNC(x) (((x) & 0xff) << 8) > +/* VIDEO_LIPSYNC, AUDIO_LIPSYNC > + * 0 = invalid > + * x = legal delay value > + * 255 = sync not supported > + */ Hmm, AMD_HDA_verbs_v2.pdf says that: 0 = unknown latency HDMI spec 1.4 says that: 0 = not valid or unknown latency 1..251 = valid delay value 255 = video not supported / audio not supported Are you sure you shouldn't use 0 instead for unknown (no latency_present)? Not sure this matters much, though, since the only consumer here is ALSA which we can write however we wish (and it is missing handling for 255 since it was missing from AMD_HDA_verbs_v2.pdf, but I'll add it in any case since it is mentioned in HDMI specs). [...] -- Anssi Hannula