From patchwork Sun Mar 27 23:52:46 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mario Kleiner X-Patchwork-Id: 8677521 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8152F9F36E for ; Sun, 27 Mar 2016 23:53:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6C0062021F for ; Sun, 27 Mar 2016 23:53:31 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 5C87920218 for ; Sun, 27 Mar 2016 23:53:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D32096E356; Sun, 27 Mar 2016 23:53:26 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-wm0-x235.google.com (mail-wm0-x235.google.com [IPv6:2a00:1450:400c:c09::235]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6C86D6E2E7 for ; Sun, 27 Mar 2016 23:53:14 +0000 (UTC) Received: by mail-wm0-x235.google.com with SMTP id 20so667906wmh.1 for ; Sun, 27 Mar 2016 16:53:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2SuaOOVlbSvnkDDKHXJtNhdaKQgFq1VFwhoKeCAr97Y=; b=Y/NjeZjXsJDmTEo2yIOHP5RA4w2zfHp2RWHVEH2Ipd3PR2zopUkoNCAV7IuRZXNgbj SBTcKx2kNUCu67NGEvzklqBHa6a1Y1GODkEC/OrKtQexJQ+UfcrzHSFDKwcHpIAXSdU1 ln/c/Dhu7dKWULFLqnEjWm5BIPjCFjds2DxlTlNxqUW6SpF+05yPnMw586GM6KpIYYMK VPQxCVtsm1OjYXZJXDLYf7i6wvYAMweQVtLZA4QQDXcYORde+Qna1bvpftx2soYc/UiM /GrQzXtlyaHaQK3J/91E/GAMVfhIDrDDKIjwKGV2FIkugnZ5dGA6p73DLXxzdj/h8iBc uvCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=2SuaOOVlbSvnkDDKHXJtNhdaKQgFq1VFwhoKeCAr97Y=; b=M5RYLmuS3Y+8iAjZhZcvfxuxUVRJshRAL9z5BzM2ImxDI5A/f212tAuSDZs8xnKG5y phiQ7NGaynmunYKELGTs9yNdLx72M2j2Zfbai9fjrWi65ahdnsXlV6e651CwMdkyqBPa KbVT48ikecuyW/B9lsVPEfJS0/TOzqnM9MvrNyuZqCvx+Tqd1pS/2dhvAER3NpZvwUvB EyYa7QTjqmUDHVx/5pQQ9iT/kGvAFiS0iqXqO+Xx7FCbaNFps85voxo3GSTCZlBbXlxX JAgNbMeDu0NDkAUI6L/yU9z7k6nHVihCG88dlpBNPga6j6gziN0VMdQcl+lP/HajLbJt W/3w== X-Gm-Message-State: AD7BkJK3/raW0LqmQq9s+0KqDD5uzaf9t5oBA5hHaXxc+DSfv3sZnvYDUFqLKwXeYx5bMw== X-Received: by 10.194.75.196 with SMTP id e4mr24872642wjw.134.1459122792288; Sun, 27 Mar 2016 16:53:12 -0700 (PDT) Received: from twisty.cin.medizin.uni-tuebingen.de (cin-11.medizin.uni-tuebingen.de. [134.2.118.242]) by smtp.gmail.com with ESMTPSA id o16sm22327412wjr.9.2016.03.27.16.53.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 27 Mar 2016 16:53:11 -0700 (PDT) From: Mario Kleiner To: dri-devel@lists.freedesktop.org Subject: [PATCH 2/3] drm/i915/dp: Try to find proper bpc for DP->legacy converters. Date: Mon, 28 Mar 2016 01:52:46 +0200 Message-Id: <1459122767-13314-3-git-send-email-mario.kleiner.de@gmail.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1459122767-13314-1-git-send-email-mario.kleiner.de@gmail.com> References: <1459122767-13314-1-git-send-email-mario.kleiner.de@gmail.com> MIME-Version: 1.0 Cc: Jani Nikula , Daniel Vetter , stable@vger.kernel.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This fixes a regression in output precision for DVI and VGA video sinks connected to Intel hw via active DisplayPort->DVI/VGA converters. The regression was indirectly introduced by commit 013dd9e03872 ("drm/i915/dp: fall back to 18 bpp when sink capability is unknown"). Our current drm edid 1.3 handling can't reliably assign a proper minimum supported display depth of 8 bpc to all DVI sinks, as mandated by DVI 1.0 spec, section 2.2.11.2 "Monitor data format support", but returns 0 bpc = "Don't know" instead. For analog VGA sinks it also returns 0 bpc, although those sinks themselves have infinite color depth, only restricted by the DAC resolution of the encoder. If a VGA or dual-link DVI display is connected via DisplayPort connector then due to above commit the driver would fall back to only 6 bpc, which would cause degradation for DVI and VGA displays, annoying in general, but especially harmful for application of display devices used in neuroscience research and for medical diagnosic which absolutely need native non-dithered 8 bpc at a minimum to operate correctly. For DP connectors with bpc == 0 according to EDID, fix this problem by checking the dpcd data to find out if a DP->legacy converter is connected. If the converter is DP->DVI/HDMI assume 8 bpc depth. If the converter is DP->VGA assume at least 8 bpc, but try to get a more accurate value (8, 10, 12 or 16 bpc) if the converter exposes this info. As the "fall back to 18 bpp" patch was backported to stable we should include this one also into stable to fix the regression in color depth for such panels. Tested with MiniDP->DP adapter, MiniDP->HDMI adapter, MiniDP->single-link DVI adapter, MiniDP->dual-link DVI active adapter, and Apple MiniDP->VGA active adapter. Signed-off-by: Mario Kleiner Cc: Jani Nikula Cc: Ville Syrjälä Cc: Daniel Vetter Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/intel_display.c | 12 ++++++++ drivers/gpu/drm/i915/intel_dp.c | 56 ++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_drv.h | 1 + 3 files changed, 69 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 6e0d828..9903949 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -12018,12 +12018,24 @@ connected_sink_compute_bpp(struct intel_connector *connector, if (connector->base.display_info.bpc == 0) { int type = connector->base.connector_type; int clamp_bpp = 24; + int legacy_bpc = 0; /* Fall back to 18 bpp when DP sink capability is unknown. */ if (type == DRM_MODE_CONNECTOR_DisplayPort || type == DRM_MODE_CONNECTOR_eDP) clamp_bpp = 18; + /* On DP to legacy converter, try harder to find sink bpc */ + if (type == DRM_MODE_CONNECTOR_DisplayPort) { + legacy_bpc = intel_dp_legacy_bpc(&connector->base); + + if (legacy_bpc) { + DRM_DEBUG_KMS("DP to VGA/DVI/HDMI converter with bpc %d\n", + legacy_bpc); + clamp_bpp = 3 * legacy_bpc; + } + } + if (bpp > clamp_bpp) { DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of %d\n", bpp, clamp_bpp); diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index f069a82..963a8f8 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -6117,3 +6117,59 @@ void intel_dp_mst_resume(struct drm_device *dev) } } } + +/* XXX Needs work for more than 1 downstream port */ +int intel_dp_legacy_bpc(struct drm_connector *connector) +{ + struct intel_dp *intel_dp = intel_attached_dp(connector); + uint8_t *dpcd = intel_dp->dpcd; + uint8_t type; + int bpc = 0; + + /* if there's no downstream port, then this can't be DP->legacy */ + if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT)) + return bpc; + + /* Basic type of downstream ports */ + type = intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DWN_STRM_PORT_TYPE_MASK; + + /* + * Lacking other info, 8 bpc is a reasonable start for analog out. + * E.g., Apple MiniDP->VGA adaptors don't provide more info than + * that. Despite having DP_DPCD_REV == 0x11 their downstream_ports + * descriptor is empty - all zeros. + */ + if (type == DP_DWN_STRM_PORT_TYPE_ANALOG) + bpc = 8; + + if (intel_dp->dpcd[DP_DPCD_REV] < 0x11) + return bpc; + + /* Rev 1.1+. More specific downstream port type available */ + type = intel_dp->downstream_ports[0] & DP_DS_PORT_TYPE_MASK; + + /* VGA, DVI and HDMI support at least 8 bpc */ + if (type == DP_DS_PORT_TYPE_VGA || type == DP_DS_PORT_TYPE_DVI || + type == DP_DS_PORT_TYPE_HDMI) + bpc = 8; + + /* As of DP interop v1.1a only VGA defines additional detail */ + if (type != DP_DS_PORT_TYPE_VGA || + !(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE)) + return bpc; + + /* VGA with DP_DETAILED_CAP_INFO_AVAILABLE provides bpc info */ + switch (intel_dp->downstream_ports[2] & DP_DS_VGA_MAX_BPC_MASK) { + case DP_DS_VGA_8BPC: + return 8; + case DP_DS_VGA_10BPC: + return 10; + case DP_DS_VGA_12BPC: + return 12; + case DP_DS_VGA_16BPC: + return 16; + } + + return bpc; +} diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 4c027d6..6692788 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1253,6 +1253,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp); void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector); void intel_dp_mst_suspend(struct drm_device *dev); void intel_dp_mst_resume(struct drm_device *dev); +int intel_dp_legacy_bpc(struct drm_connector *connector); int intel_dp_max_link_rate(struct intel_dp *intel_dp); int intel_dp_rate_select(struct intel_dp *intel_dp, int rate); void intel_dp_hot_plug(struct intel_encoder *intel_encoder);