From patchwork Wed Oct 30 08:41:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Nautiyal, Ankit K" X-Patchwork-Id: 13856125 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 3DEC1D7497F for ; Wed, 30 Oct 2024 08:38:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8F70910E75D; Wed, 30 Oct 2024 08:38:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="UhHam3sE"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2144510E75D; Wed, 30 Oct 2024 08:38:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1730277521; x=1761813521; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=4/rLEAmFlHp23flk99P6eyjjFH8YOesEG0mWlxAX7c0=; b=UhHam3sEnw08nKTEEkIW/HhJtDodJdGqPfJUbZorZRPyoTJW1k6xbM6q qh7tXoMHNUCCQKT/rH/yzy3wBPBfoK3/Y4F//FjAZyFuXIkyCIYJNDpKB lmEQj9CehJmxhiqsOVZv2ZvZVDdFZPTbhoLi5pjfIwpr90mKywmPWVb8E lF0mYRKzJ/gIPj/fsBU5rkN0KhmMDEGgnzrXLVJv8lAPXDcHFzUlQnwJD vI6rp9w9Ge4GYBr6Tf31ChLTUClGy36FnyymV/a8xWMp6BdkLdBiuc7JY B4Vbdi9T/Q4Vi6dniQ9vL0r339NWUrZbme5yIoh9m5aae+Ze2vxbRpxpt A==; X-CSE-ConnectionGUID: mr5ShvdjQ5WCUbCLhyJ7Ow== X-CSE-MsgGUID: ArOXKkFkRiivKpStY/9SpQ== X-IronPort-AV: E=McAfee;i="6700,10204,11222"; a="30112710" X-IronPort-AV: E=Sophos;i="6.11,199,1725346800"; d="scan'208";a="30112710" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2024 01:38:40 -0700 X-CSE-ConnectionGUID: n0xcDH5nTyaWCy6lp/UikA== X-CSE-MsgGUID: 6kx5SJgDReufkuAy8xxEdQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,244,1725346800"; d="scan'208";a="82407987" Received: from srr4-3-linux-103-aknautiy.iind.intel.com ([10.223.34.160]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2024 01:38:38 -0700 From: Ankit Nautiyal To: intel-gfx@lists.freedesktop.org Cc: intel-xe@lists.freedesktop.org Subject: [PATCH] drm/i915/dp: Limit max compressed bpp to 18 when forcing DSC Date: Wed, 30 Oct 2024 14:11:00 +0530 Message-ID: <20241030084100.1361689-1-ankit.k.nautiyal@intel.com> X-Mailer: git-send-email 2.45.2 MIME-Version: 1.0 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" While forcing DSC when it is not actually required, the max compressed bpp from the source gets picked for compression for some pipe bpps. Apparently, when DSC is not required, forcing DSC to the maximum compressed bpp seems to cause underruns. To avoid this, limit the max compressed bpp to 18 while forcing DSC. This value works across platforms with different pipe bpps and prevents underruns. Signed-off-by: Ankit Nautiyal Reviewed-by: Naga Venkata Srikanth V --- drivers/gpu/drm/i915/display/intel_dp.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 28fa5e2d0c33..0ce29cefaa13 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2021,6 +2021,15 @@ static int dsc_src_max_compressed_bpp(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); + /* + * Forcing DSC and using the platform's max compressed bpp is seen to cause + * underruns. Since DSC isn't needed in these cases, limit the + * max compressed bpp to 18, which is a safe value across platforms with different + * pipe bpps. + */ + if (intel_dp->force_dsc_en) + return 18; + /* * Max Compressed bpp for Gen 13+ is 27bpp. * For earlier platform is 23bpp. (Bspec:49259).