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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 AFEDBC352A3 for ; Tue, 11 Feb 2020 18:34:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9378924650 for ; Tue, 11 Feb 2020 18:34:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NeATpCD3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730450AbgBKSed (ORCPT ); Tue, 11 Feb 2020 13:34:33 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:32894 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728301AbgBKSed (ORCPT ); Tue, 11 Feb 2020 13:34:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581446072; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PZq825i0coPwIgxr8swXpBmvjatE/H/TFgDNYkwo1tw=; b=NeATpCD3payVeDzOUUj/XjD7HrmPkV1GYnv7S9hvxuAGChKPYE0mG02Eya9MDPUbuao0be 0Wdws7o/hU0uxIko1D5FUjP2e5YM/90hz3K4qJCut0L/CamaThgCME7Ay5rK2TkAGJrDcl gAsZRtErhaqHuOzp9lioyh0PFlHGeG0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-173-xhF_iuDPOMutTJmjH0YFwQ-1; Tue, 11 Feb 2020 13:34:22 -0500 X-MC-Unique: xhF_iuDPOMutTJmjH0YFwQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E07F9800D48; Tue, 11 Feb 2020 18:34:19 +0000 (UTC) Received: from Ruby.bss.redhat.com (dhcp-10-20-1-196.bss.redhat.com [10.20.1.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 48E555C100; Tue, 11 Feb 2020 18:34:18 +0000 (UTC) From: Lyude Paul To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Jani Nikula , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Chris Wilson , Juha-Pekka Heikkila , Lee Shawn C , linux-kernel@vger.kernel.org Subject: [PATCH v2 2/3] drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED panel Date: Tue, 11 Feb 2020 13:33:47 -0500 Message-Id: <20200211183358.157448-3-lyude@redhat.com> In-Reply-To: <20200211183358.157448-1-lyude@redhat.com> References: <20200211183358.157448-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The X1 Extreme is one of the systems that lies about which backlight interface that it uses in its VBIOS as PWM backlight controls don't work at all on this machine. It's possible that this panel could be one of the infamous ones that can switch between PWM mode and DPCD backlight control mode, but we haven't gotten any more details on this from Lenovo just yet. For the time being though, making sure the backlight 'just works' is a bit more important. So, add a quirk to force DPCD backlight controls on for these systems based on EDID (since this panel doesn't appear to fill in the device ID). Hopefully in the future we'll figure out a better way of probing this. Signed-off-by: Lyude Paul Cc: Jani Nikula --- drivers/gpu/drm/drm_dp_helper.c | 4 +++ .../drm/i915/display/intel_dp_aux_backlight.c | 25 ++++++++++++++++--- include/drm/drm_dp_helper.h | 10 ++++++++ 3 files changed, 35 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_hel= per.c index db23308f4d8b..a39c3cdacb20 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1236,6 +1236,10 @@ struct edid_quirk { * DP quirks in such cases. */ static const struct edid_quirk edid_quirk_list[] =3D { + /* Optional 4K AMOLED panel in the ThinkPad X1 Extreme 2nd Generation + * only supports DPCD backlight controls + */ + { MFG(0x4c, 0x83), PROD_ID(0x41, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIG= HT) }, }; =20 #undef MFG diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/driv= ers/gpu/drm/i915/display/intel_dp_aux_backlight.c index 48276237b362..35a19c0314fa 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -328,15 +328,32 @@ intel_dp_aux_display_control_capable(struct intel_c= onnector *connector) int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_conn= ector) { struct intel_panel *panel =3D &intel_connector->panel; - struct drm_i915_private *dev_priv =3D to_i915(intel_connector->base.dev= ); + struct intel_dp *intel_dp =3D enc_to_intel_dp(intel_connector->encoder)= ; + struct drm_device *dev =3D intel_connector->base.dev; + struct drm_i915_private *dev_priv =3D to_i915(dev); =20 if (i915_modparams.enable_dpcd_backlight =3D=3D 0 || - (i915_modparams.enable_dpcd_backlight =3D=3D -1 && - dev_priv->vbt.backlight.type !=3D INTEL_BACKLIGHT_VESA_EDP_AUX_INTE= RFACE)) + !intel_dp_aux_display_control_capable(intel_connector)) return -ENODEV; =20 - if (!intel_dp_aux_display_control_capable(intel_connector)) + /* + * There are a lot of machines that don't advertise the backlight + * control interface to use properly in their VBIOS, :\ + */ + if (dev_priv->vbt.backlight.type !=3D + INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE && + !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks, + DP_QUIRK_FORCE_DPCD_BACKLIGHT)) { + DRM_DEV_INFO(dev->dev, + "Panel advertises DPCD backlight support, but " + "VBT disagrees. If your backlight controls " + "don't work try booting with " + "i915.enable_dpcd_backlight=3D1. If your machine " + "needs this, please file a _new_ bug report on " + "bugs.freedesktop.org against DRI -> " + "DRM/Intel\n"); return -ENODEV; + } =20 panel->backlight.setup =3D intel_dp_aux_setup_backlight; panel->backlight.enable =3D intel_dp_aux_enable_backlight; diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 7f5dd2ee4a94..c5580e988826 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1535,6 +1535,16 @@ enum drm_dp_quirk { * The DSC caps can be read from the physical aux instead. */ DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD, + /** + * @DP_QUIRK_FORCE_DPCD_BACKLIGHT: + * + * The device is telling the truth when it says that it uses DPCD + * backlight controls, even if the system's firmware disagrees. This + * quirk should be checked against both the ident and panel EDID. + * When present, the driver should honor the DPCD backlight + * capabilities advertised. + */ + DP_QUIRK_FORCE_DPCD_BACKLIGHT, }; =20 /** --=20 2.24.1