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 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 2D9B4CA1005 for ; Tue, 2 Sep 2025 13:46:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B5D0F10E727; Tue, 2 Sep 2025 13:46:49 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iAbbfz/B"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1B9BE10E32F; Tue, 2 Sep 2025 13:46:48 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id C4EF160218; Tue, 2 Sep 2025 13:46:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2446AC4CEED; Tue, 2 Sep 2025 13:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756820806; bh=bAeXueErPR9FkS1aVpvm+MMOl2yBOa/fjOiWjXbDGL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iAbbfz/BfllIGjxeaTYvYWAtfCWDX8J3HPvG5zM3tReajV2NZ6EVmZRJlVzSqGBf8 Ysx/ACfbEwxMl66X9v3sRSpS3996sFtJXH+jw5fyvvuKMcdhFl5sYTkwdNIaR3pqyx VixO4td4+eTl7xk/5qQLrBTvqQH2U9qw+bn0KQBE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Sasha Levin , Imre Deak Subject: [PATCH 5.4 23/23] Revert "drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS" Date: Tue, 2 Sep 2025 15:22:09 +0200 Message-ID: <20250902131925.659286447@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250902131924.720400762@linuxfoundation.org> References: <20250902131924.720400762@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Imre Deak This reverts commit 2402adce8da4e7396b63b5ffa71e1fa16e5fe5c4 which is commit a40c5d727b8111b5db424a1e43e14a1dcce1e77f upstream. The upstream commit a40c5d727b8111b5db424a1e43e14a1dcce1e77f ("drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS") the reverted commit backported causes a regression, on one eDP panel at least resulting in display flickering, described in detail at the Link: below. The issue fixed by the upstream commit will need a different solution, revert the backport for now. Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Cc: Sasha Levin Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14558 Signed-off-by: Imre Deak Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_dp_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -280,7 +280,7 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_a * We just have to do it before any DPCD access and hope that the * monitor doesn't power down exactly after the throw away read. */ - ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_LANE0_1_STATUS, buffer, + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer, 1); if (ret != 1) goto out;