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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no 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 E92E7C43331 for ; Mon, 30 Mar 2020 16:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A8D4820578 for ; Mon, 30 Mar 2020 16:30:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OhDgcVYk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729004AbgC3QaN (ORCPT ); Mon, 30 Mar 2020 12:30:13 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:41297 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726085AbgC3QaN (ORCPT ); Mon, 30 Mar 2020 12:30:13 -0400 Received: by mail-pg1-f194.google.com with SMTP id b1so8890598pgm.8 for ; Mon, 30 Mar 2020 09:30:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=HxfNuI2iG4J1qKdJFFaM5eKiU091xw17n/pAcgsjklg=; b=OhDgcVYkpggTTlgIL1zbHaw5aMKxRVjpTk+SNPYyMBGbybwmeZOkAWl6IEBhgZOLnD sWe0CfXXZqusgiClTU0nbEVrcRrHG0e8XAd4jFKO6l3IjQDs6psRYzPgqOQsSrWnkqou zKFN7+yuyGThuCFe4JGIgx1eyGDisMQT81O927yKUDB28iimk0KQSVExn/QW36QsZB+C +e05ru4CWs1goUWIY002rXU+Q7GIfeJKq7jWc4Nw/8wKXHcEKtwpFXHHXf7CZwqbv1US JCgfVAJ5/gdNfeTFX6XsWJAoOYrOgBtKMOzbUIx8HtqAC8ZxnFHaFQwUMMcJWsnbIi+T rP6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=HxfNuI2iG4J1qKdJFFaM5eKiU091xw17n/pAcgsjklg=; b=UlNb6on2U1yw067Zxs4s+UaVXu1t22EQxYBTiiCLGkqiGYfTPgjCRceIi/ofbXJ/lF /9VMaJj823wwg1pnHR9PScY7ch6wsNQPO7hh8SxzYKujntCsrBTV/UXysHEw1NY8VefB ZjLpeuJG0JHZz88BsdfsUwN75NgXzF1WFWgLkD8qpI1tqdCliGl0r0q2//sJBcimL2I5 MA8+bpDishcfrIbXSK3Csu13IoiMjhx+rjNY7LO1kKz1uMImtl8wRRHyxrK3GZ7eM7cA wqsL0JtGAH22q+83mXwVq99GSrT0rBQf8RNHbjH2QdAf51SyjbPEe2YflO2V6td2/KSs 2eUg== X-Gm-Message-State: ANhLgQ2JB8qp31hQCjqOU2tUcJe8+kMDaAxWD4bBLJFtPPUkHXghOEJK DmC6vClv7fITVHPEP3j8yHFkz4Ke X-Google-Smtp-Source: ADFU+vthwNXtBGqBEVSC0GzYBd7kuRmS/miaLv6x5vJsvdfAAdNkMDYMhpXlRg7eN3sINL26lRKWuw== X-Received: by 2002:a63:cb4a:: with SMTP id m10mr13998178pgi.101.1585585811879; Mon, 30 Mar 2020 09:30:11 -0700 (PDT) Received: from sultan-box.localdomain (static-198-54-129-52.cust.tzulo.com. [198.54.129.52]) by smtp.gmail.com with ESMTPSA id mu15sm14398pjb.30.2020.03.30.09.30.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Mar 2020 09:30:11 -0700 (PDT) From: Sultan Alsawaf X-Google-Original-From: Sultan Alsawaf To: linux-kernel@vger.kernel.org Cc: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Sultan Alsawaf Subject: [PATCH 0/1] drm/i915: Disable Panel Self Refresh (PSR) by default Date: Mon, 30 Mar 2020 09:30:05 -0700 Message-Id: <20200330163006.4064-1-sultan@kerneltoast.com> X-Mailer: git-send-email 2.26.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sultan Alsawaf Hi, Laptops which support an esoteric power-saving mechanism called Panel Self Refresh (PSR) suffer from severe graphical corruption and flickering. Enabled by default in 5.0, PSR causes graphical corruption to the point of unusability on many Dell laptops made within the past few years, since they typically support PSR. A bug was filed with Intel several months ago for this with more information [1]. I suspect most of the community hasn't been affected by this bug because ThinkPads and many other laptops I checked didn't support PSR. As of writing, the issues I observed with PSR are neither fully fixed in Intel's drm-tip branch nor in 5.6. Disabling PSR by default brings us safely back to pre-5.0 behavior, remedying the glitches. Also, Ubuntu now ships with PSR disabled by default in its affected kernels, so there is distro support behind this change. Thanks, Sultan [1] https://gitlab.freedesktop.org/drm/intel/issues/425 Sultan Alsawaf (1): drm/i915: Disable Panel Self Refresh (PSR) by default drivers/gpu/drm/i915/i915_params.c | 3 +-- drivers/gpu/drm/i915/i915_params.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) -- 2.26.0