From patchwork Mon Mar 25 21:56:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 13603029 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 36BEDC54E58 for ; Mon, 25 Mar 2024 21:57:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9ABCA10EB15; Mon, 25 Mar 2024 21:57:00 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b="Ej+nPdl8"; dkim-atps=neutral Received: from mail-pg1-f179.google.com (mail-pg1-f179.google.com [209.85.215.179]) by gabe.freedesktop.org (Postfix) with ESMTPS id 21EEE10EB1E for ; Mon, 25 Mar 2024 21:56:59 +0000 (UTC) Received: by mail-pg1-f179.google.com with SMTP id 41be03b00d2f7-5f034b4dcecso2439756a12.1 for ; Mon, 25 Mar 2024 14:56:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1711403818; x=1712008618; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=UR7sFSEYjP8BO01JVRD78Toou7R7NTsnLZcSYy9yMLk=; b=Ej+nPdl8xB/iegBeQVk9mpbd3oHOxE4Ix+7kTl/LSiyh9+1TF1MRCz2vAwM/3/oar5 NNVJIEmE5InkRqelBuLUpSuJ3GwQ+pO2lOHa05r2OnqNLOp9judfLcvtzV0yoe9+jvvs BDjQJN1u4o0pWKJG0CkBIp03f8f8lN/EhtMFo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711403818; x=1712008618; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=UR7sFSEYjP8BO01JVRD78Toou7R7NTsnLZcSYy9yMLk=; b=T6axy1xF9i5tLrvD7vf/w/Jld24YlUdw9fkmCZR9Lzis9ubFo/MSZv6nL0II2hBZdA AJ60v70jO4g5UTTVMJj/jDYmCQBD4gi09D09nvUrt4nck0Mo0M0Tuh/ZF2yZqoV4PKFN fBAf03gZnYYPxYhH9EuJRoQBCFQQHpQtPHDAn9tsXg7/ruoinhzTnICHsUUYrDm1Mm/p Y5m53239l3be4iOwyU0/AtJnCWkvT7BJ7eBQ4hB6oxLek/qVpIrOCGra+Zcs7lZf05Yr tMJoU98cbvvlhsSFwoeOkWOp/soOOdpHejwnbgSzOE6/Y9lqb1jf2RxZ3zgpniH3OoW7 R7Vg== X-Gm-Message-State: AOJu0YyFc3RHbtZ66MVxhytafEzGcBjTX1DfSq/RYLYkEkzqt/eCCaAF rAG7Vg0m2BfA9VXBhV8TNt0fZu2Njp4LlJxx0S2CI3Lln6t5Usd/N2yV8bSrxdh/RMsKrY6CNXA = X-Google-Smtp-Source: AGHT+IFvvymI/+nAjVhwHLdNpVFDRLNACuh+o6MvjynK0XJWPebIEwChaIwn4LWdWp8KHSfw+SjCnQ== X-Received: by 2002:a17:902:ec8f:b0:1e0:73d:9172 with SMTP id x15-20020a170902ec8f00b001e0073d9172mr10772950plg.23.1711403817749; Mon, 25 Mar 2024 14:56:57 -0700 (PDT) Received: from dianders.sjc.corp.google.com ([2620:15c:9d:2:f21b:7dde:93cc:b987]) by smtp.gmail.com with ESMTPSA id n6-20020a170902e54600b001def0897284sm5207866plf.76.2024.03.25.14.56.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Mar 2024 14:56:57 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org Cc: Pin-yen Lin , Prahlad Kilambi , Hsin-Yi Wang , Douglas Anderson , Daniel Vetter , David Airlie , Jessica Zhang , Maarten Lankhorst , Maxime Ripard , Neil Armstrong , Sam Ravnborg , Thomas Zimmermann , linux-kernel@vger.kernel.org Subject: [PATCH 0/3] drm-panel: Don't make failures quite so fatal Date: Mon, 25 Mar 2024 14:56:24 -0700 Message-ID: <20240325215631.3804796-1-dianders@chromium.org> X-Mailer: git-send-email 2.44.0.396.g6e790dbe36-goog MIME-Version: 1.0 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This patch series is born out of the observation that after several Chromebooks transitioned over to the generic "edp-panel" compatible string that we received a number of in-the-field reports of the primary graphics device for the Chromebook not coming up. The current belief is that these Chromebooks are actually suffering from a true hardware failure and the panel is either fully disconnected or it has some type of intermittent connection. While we can't solve that problem, digging showed that we actually dealt with this situation better _before_ switching to the generic "edp-panel" compatible string. Before switching to "edp-panel", devices using eDP would finish their probe and would actually not show any failure until you tried to turn the panel on. That was a _good_ thing. The component model used by many DRM devices means that if the panel doesn't finish probing that the rest of the DRM device doesn't probe. In turn, that means that any other display adapters (like ones that would allow hooking up an external display) don't probe. The end result was that a device with a broken panel that could have continued to be a useful computer by hooking up an external display became e-waste. I won't say that this series is the most elegant/wonderful thing in the world. Ideally we could fail the probe of the panel and still use the external display. That's a pretty serious re-design, though. DRM devices work like they do with the component model because of some of their inherent complexities. Douglas Anderson (3): drm/panel-edp: Abstract out function to set conservative timings drm/panel-edp: If we fail to powerup/get EDID, use conservative timings drm-panel: If drm_panel_dp_aux_backlight() fails, don't fail panel probe drivers/gpu/drm/panel/panel-edp.c | 60 +++++++++++-------- .../gpu/drm/panel/panel-samsung-atna33xc20.c | 9 ++- 2 files changed, 41 insertions(+), 28 deletions(-)