From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DF94351FDB; Fri, 21 Nov 2025 13:54:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763733247; cv=none; b=ZiEOWzLb/R4DUWAHvPQ0tEG0yD2MzsB9fdXWMp/pwUDkSC21cRcvRS3QG0yZLdcxCB/kPlXqUGFu0z4KbfDcJPr31+7+VoLligGFM/oiz1lIxfZ0wg49ABDrnPaZFvGDmaNJq1qzqST1GW/rmrLK2gq9eStqPHlDR1SPYm4s7VE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763733247; c=relaxed/simple; bh=r6GTFkaPzG/m00rGu5V6cKZUrMhyEX4H9BYVy3E38ZQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Dn+5c7OzdXcNMUa3g8StetOWuPiOoe3gr2qQMqvGpWSNAI11hVnAHTTzqLNwLeHz7f8SfSVvzN3dYTEzFToHogTX1NJ2PqbfKoLuz4xHEAHqWWcC4d64dWeJ8B0QEIVOivPIA9GluKb8r6i/RjngBJ6grP8BiaNV+y4UjIg5Src= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=z3ZPqAm6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="z3ZPqAm6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D9D3C4CEF1; Fri, 21 Nov 2025 13:54:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763733247; bh=r6GTFkaPzG/m00rGu5V6cKZUrMhyEX4H9BYVy3E38ZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z3ZPqAm6IOLCBtnCW05TRWzftKQgJtXsJeAFOoWHtNK11dyhL4paDrKsTbQ8I3Kva XDVZXCfX+Ss8VpEybrTCyFZqmjyuOfoppJQ1xjBQ+UuONMeeC0d3DV7yWndogN/6aO 9mROpZlQcHzbd8k3mDTQXMfqRstwlFlKL/tDhHEw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alex Deucher , =?UTF-8?q?Timur=20Krist=C3=B3f?= , Sasha Levin Subject: [PATCH 6.6 385/529] drm/amd/pm: Disable MCLK switching on SI at high pixel clocks Date: Fri, 21 Nov 2025 14:11:24 +0100 Message-ID: <20251121130244.723301797@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130230.985163914@linuxfoundation.org> References: <20251121130230.985163914@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Timur Kristóf [ Upstream commit 5c05bcf6ae7732da1bd4dc1958d527b5f07f216a ] On various SI GPUs, a flickering can be observed near the bottom edge of the screen when using a single 4K 60Hz monitor over DP. Disabling MCLK switching works around this problem. Reviewed-by: Alex Deucher Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c index 2863dc65ffc6f..e5f68b2b8def3 100644 --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c @@ -3485,6 +3485,11 @@ static void si_apply_state_adjust_rules(struct amdgpu_device *adev, * for these GPUs to calculate bandwidth requirements. */ if (high_pixelclock_count) { + /* Work around flickering lines at the bottom edge + * of the screen when using a single 4K 60Hz monitor. + */ + disable_mclk_switching = true; + /* On Oland, we observe some flickering when two 4K 60Hz * displays are connected, possibly because voltage is too low. * Raise the voltage by requiring a higher SCLK. -- 2.51.0