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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6377C282DD for ; Thu, 9 Jan 2020 15:38:23 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C77C82067D for ; Thu, 9 Jan 2020 15:38:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C77C82067D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CBAF96E43F; Thu, 9 Jan 2020 15:38:21 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id DBB756E441; Thu, 9 Jan 2020 15:38:19 +0000 (UTC) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Jan 2020 07:38:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,414,1571727600"; d="scan'208";a="211928654" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by orsmga007.jf.intel.com with SMTP; 09 Jan 2020 07:38:16 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 09 Jan 2020 17:38:15 +0200 Date: Thu, 9 Jan 2020 17:38:15 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Mario Kleiner Subject: Re: [PATCH] drm/i915/dp: Add current maximum eDP link rate to sink_rate array. Message-ID: <20200109153815.GQ1208@intel.com> References: <20200109150752.28098-1-mario.kleiner.de@gmail.com> <20200109152656.GP1208@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200109152656.GP1208@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mario.kleiner.de@gmail.de, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Daniel Vetter Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Jan 09, 2020 at 05:26:57PM +0200, Ville Syrj=E4l=E4 wrote: > On Thu, Jan 09, 2020 at 04:07:52PM +0100, Mario Kleiner wrote: > > If the current eDP link rate, as read from hw, provides a > > higher bandwidth than the standard link rates, then add the > > current link rate to the link_rates array for consideration > > in future mode-sets. > > = > > These initial current eDP link settings have been set up by > > firmware during boot, so they should work on the eDP panel. > > Therefore use them if the firmware thinks they are good and > > they provide higher link bandwidth, e.g., to enable higher > > resolutions / color depths. > > = > > This fixes a problem found on the MacBookPro 2017 Retina panel: > > = > > The panel reports 10 bpc color depth in its EDID, and the UEFI > > firmware chooses link settings at boot which support enough > > bandwidth for 10 bpc (324000 kbit/sec to be precise), but the > > DP_MAX_LINK_RATE dpcd register only reports 2.7 Gbps as possible, Does it actually or do we just ignore the fact that it reports 3.24Gbps? If it really reports 3.24 then we should be able to just add that to dp_rates[] in intel_dp_set_sink_rates() and be done with it. Although we'd likely want to skip 3.24 unless it really is reported as the max so as to not use that non-standard rate on other displays. So would require a bit fancier logic for that. > > so intel_dp_set_sink_rates() would cap at that. This restricts > > achievable color depth to 8 bpc, not providing the full color > > depth of the panel. With this commit, we can use firmware setting > > and get the full 10 bpc advertised by the Retina panel. > > = > > Signed-off-by: Mario Kleiner > > Cc: Daniel Vetter > > --- > > drivers/gpu/drm/i915/display/intel_dp.c | 23 +++++++++++++++++++++++ > > 1 file changed, 23 insertions(+) > > = > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/= i915/display/intel_dp.c > > index 2f31d226c6eb..aa3e0b5108c6 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > @@ -4368,6 +4368,8 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) > > { > > struct drm_i915_private *dev_priv =3D > > to_i915(dp_to_dig_port(intel_dp)->base.base.dev); > > + int max_rate; > > + u8 link_bw; > > = > > /* this function is meant to be called only once */ > > WARN_ON(intel_dp->dpcd[DP_DPCD_REV] !=3D 0); > > @@ -4433,6 +4435,27 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) > > else > > intel_dp_set_sink_rates(intel_dp); > > = > > + /* > > + * If the firmware programmed a rate higher than the standard sink ra= tes > > + * during boot, then add that rate as a valid sink rate, as fw knows > > + * this is a good rate and we get extra bandwidth. > > + * > > + * Helps, e.g., on the Apple MacBookPro 2017 Retina panel, which is o= nly > > + * eDP 1.1, but supports the unusual rate of 324000 kHz at bootup, for > > + * 10 bpc / 30 bit color depth. > > + */ > > + if (!intel_dp->use_rate_select && > > + (drm_dp_dpcd_read(&intel_dp->aux, DP_LINK_BW_SET, &link_bw, 1) = =3D=3D 1) && > > + (link_bw > 0) && (intel_dp->num_sink_rates < DP_MAX_SUPPORTED_RAT= ES)) { > > + max_rate =3D drm_dp_bw_code_to_link_rate(link_bw); > > + if (max_rate > intel_dp->sink_rates[intel_dp->num_sink_rates - 1]) { > > + intel_dp->sink_rates[intel_dp->num_sink_rates] =3D max_rate; > > + intel_dp->num_sink_rates++; > > + DRM_DEBUG_KMS("Adding max bandwidth eDP rate %d kHz.\n", > > + max_rate); > > + } > = > Hmm. I guess we could do this. But plese put it into a separate > function so we don't end up with that super ugly if condition. > = > The debug message should probably be a bit more explicit. Eg. = > something like: = > "Firmware using non-standard link rate %d kHz. Including it in sink rates= .\n" > = > I'm also wondering if we shouldn't just add the link rate to the sink > rates regradless of whether it's the highest rate or not... > = > > + } > > + > > intel_dp_set_common_rates(intel_dp); > > = > > /* Read the eDP DSC DPCD registers */ > > -- = > > 2.24.0 > > = > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > = > -- = > Ville Syrj=E4l=E4 > Intel -- = Ville Syrj=E4l=E4 Intel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel