From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5F259FD9E34 for ; Fri, 27 Feb 2026 05:49:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 18FA010EA42; Fri, 27 Feb 2026 05:49:56 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="A1a7q8rh"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) by gabe.freedesktop.org (Postfix) with ESMTPS id EB77E10EA42; Fri, 27 Feb 2026 05:49:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1772171395; x=1803707395; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=VeSi5q1Mjdq3MHr+JwXrYsoq3+yKbrkatFPTdDpknQg=; b=A1a7q8rhJvUTzT2v8iaTGhX427ql2zjVyixaKpHa0O1sY5WmIivH+Hyk Vx+PLmIodYJqopcugOlC/JPu/Akxz/PI5Pi1fV4VQEBa+65hRNorqqozc TnXqfU1UfiFzZPHTH5b8UWjR0p7wnuXVaOWAxjtHyZpXLJCqvvKTbFUJP cg/oUL5wGTsHyzyExAsSKNCM9L2ccD2cwV1qAHRhplwMOFe54Eu+uqh/V yAGL3iG5udPW5Ldh6MYropoeR5WvldfhWvQ21ASqCimWiUUttHZHcPkMb FThmesqZ53p1CT72Q2vVT2rqQUCFZgQsEUKtLrorxgUNjvbLeZgUGGTKk A==; X-CSE-ConnectionGUID: 39JV1c4ZTHKMMXwVQUr/rA== X-CSE-MsgGUID: b2tt4MLvTAyBS0IFzy3Crg== X-IronPort-AV: E=McAfee;i="6800,10657,11713"; a="72280906" X-IronPort-AV: E=Sophos;i="6.21,313,1763452800"; d="scan'208";a="72280906" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Feb 2026 21:49:52 -0800 X-CSE-ConnectionGUID: l2Ztc7MYTXmlgkMqN8JPCQ== X-CSE-MsgGUID: lsVPWadBQqS/RQtMOGOl2A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,313,1763452800"; d="scan'208";a="216031670" Received: from egrumbac-mobl6.ger.corp.intel.com (HELO localhost) ([10.245.245.74]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Feb 2026 21:49:50 -0800 Date: Fri, 27 Feb 2026 07:49:47 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Ankit Nautiyal Cc: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, jouni.hogander@intel.com, animesh.manna@intel.com Subject: Re: [PATCH 08/14] drm/i915/dp: Add AS SDP support for PR with link ON Message-ID: References: <20260223134431.1639308-1-ankit.k.nautiyal@intel.com> <20260223134431.1639308-9-ankit.k.nautiyal@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Fri, Feb 27, 2026 at 06:37:37AM +0200, Ville Syrjälä wrote: > On Thu, Feb 26, 2026 at 06:10:34PM +0200, Ville Syrjälä wrote: > > On Mon, Feb 23, 2026 at 07:14:25PM +0530, Ankit Nautiyal wrote: > > > Adaptive Sync SDP (AS SDP) is also used for Panel Replay (PR). > > > For PR with Link ON, the AS SDP version V1 is used. When using > > > AS SDP Version 1, AS SDP payload and parity bytes are all set to zeroes. > > > > I don't think we should need to transmit any AS SDP in link ON mode. > > Hmm, maybe we do. While the DP spec is is extremely confusing here > (mostly just talking about the ALPM+AS SDP combo and ignoring the > link ON case), I think what it might be hinting at is that the sink > tells us whether it needs the AS SDP, via > ASYNC_VIDEO_TIMING_NOT_SUPPORTED_IN_PR. Actually no. It looks to me like with the link ON, the source is still transmitting the BS/BE at the expected locations so the sink remains synced to the source video timings, and thus the AS SDP is not needed for that. > > > > > > > > > Bspec: 75639 > > > Signed-off-by: Ankit Nautiyal > > > --- > > > drivers/gpu/drm/i915/display/intel_dp.c | 17 ++++++++++++++++- > > > 1 file changed, 16 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > > > index d08db4938638..5952db6197cf 100644 > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > > @@ -3115,7 +3115,8 @@ static bool intel_dp_needs_as_sdp(struct intel_dp *intel_dp, > > > struct intel_crtc_state *crtc_state) > > > { > > > return crtc_state->vrr.enable || > > > - crtc_state->cmrr.enable; > > > + crtc_state->cmrr.enable || > > > + crtc_state->has_panel_replay; > > > } > > > > > > static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp, > > > @@ -3137,6 +3138,16 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp, > > > as_sdp->length = 0x9; > > > as_sdp->duration_incr_ms = 0; > > > as_sdp->version = 0x2; > > > + > > > + if (crtc_state->vrr.enable) > > > + as_sdp->version = 0x2; > > > > I think we rather need some versions checks or something to > > make sure the device actually supports v2. VRR itself shouldn't > > need v2 since the v1 was originally added exactly for VRR+PCON > > use cases. PR+ALPM definitely does need v2, but not sure anything > > else actually needs it. > > > > > + else > > > + as_sdp->version = 0x1; > > > + > > > + /* No payload data bytes for Version 1 */ > > > + if (as_sdp->version == 0x1) > > > + return; > > > + > > > as_sdp->vtotal = intel_vrr_vmin_vtotal(crtc_state); > > > > > > if (crtc_state->cmrr.enable) { > > > @@ -5005,6 +5016,10 @@ static ssize_t intel_dp_as_sdp_pack(const struct drm_dp_as_sdp *as_sdp, > > > sdp->sdp_header.HB2 = as_sdp->version; > > > sdp->sdp_header.HB3 = as_sdp->length; > > > > > > + /* No Payload Data bytes for Version 1 */ > > > + if (as_sdp->version == 0x1) > > > + return length; > > > + > > > /* Fill AS (Adaptive Sync) SDP Payload */ > > > sdp->db[0] = as_sdp->mode; > > > sdp->db[1] = as_sdp->vtotal & 0xFF; > > > -- > > > 2.45.2 > > > > -- > > Ville Syrjälä > > Intel > > -- > Ville Syrjälä > Intel -- Ville Syrjälä Intel