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 E0004C83F26 for ; Mon, 28 Jul 2025 08:16:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 75C1010E4A0; Mon, 28 Jul 2025 08:16:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="NAikdUGF"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) by gabe.freedesktop.org (Postfix) with ESMTPS id 95A2410E4A1; Mon, 28 Jul 2025 08:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1753690607; x=1785226607; h=from:date:subject:mime-version:content-transfer-encoding: message-id:to:cc; bh=WhjJbOLwA7r8zgwXNtbCNU84FVuNxhReiWjMnqcJHgI=; b=NAikdUGF3vTniwJx9QPSSgxJYdaCaqGauBD2Nf1C4532tHzuQgvIDWfD 2fPmTmomaeSlHjRdSC/e8BFsc01kk4tuQ3sunzzp45tiIlLIDKWEWcDGm Ttxq96dd5wCD0ZE5BEF/637JjnRe2VTrcypqeQlZLB3CmGgwB7RckV5Xq 9bk4Z67kvtTFcr3ADrFYaHsw72Js2HxdbmyOyQmSCULkIOKsTg60zD0eF HfE7po2PhORN6JXnOy8h618Uc9whkDOedY3Pm1AOc4DdJ9idGFla3E17h BYeToqlBRdbwUTdQjI7maO8sSNCO/892Xowaxuz30CNpfV1LuhgGdbq98 Q==; X-CSE-ConnectionGUID: /zWntrvkSWyHpxbMqRyNxA== X-CSE-MsgGUID: LrNz0tN0RN6rF2yXiVnCXg== X-IronPort-AV: E=McAfee;i="6800,10657,11504"; a="55007950" X-IronPort-AV: E=Sophos;i="6.16,339,1744095600"; d="scan'208";a="55007950" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jul 2025 01:16:44 -0700 X-CSE-ConnectionGUID: PRPgYEqiSQuPGbakvgzuGw== X-CSE-MsgGUID: 5UWsRT8LRnOiPiYj3FsGbw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,339,1744095600"; d="scan'208";a="185983784" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by fmviesa002.fm.intel.com with ESMTP; 28 Jul 2025 01:16:43 -0700 From: Arun R Murthy Date: Mon, 28 Jul 2025 13:32:14 +0530 Subject: [PATCH v5] drm/i915/display: Use the recomended min_hblank values MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250728-min_hblank-v5-1-54cb7ea5cd74@intel.com> X-B4-Tracking: v=1; b=H4sIAIUuh2gC/23OQQ7CIBCF4as0rMUglEpdeQ/TGKAgE1sw0BBN0 7tLu7ELl38y8+XNKJkIJqFLNaNoMiQIvgQ/VEg76R8GQ18aUUI5OVOBR/B3pwbpn5g2TBtVE06 ERuXhFY2F94bdutI2hhFPLhr5IxrK90Rm+IQbK1rJeV8rS6/gJzMcdRhX0UGaQvxs63K9un+H5 Looqu0FU5awcrBTumVZvjKL/W/mAAAA X-Change-ID: 20250728-min_hblank-263ceb40508c To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org Cc: imre.deak@intel.com, Arun R Murthy X-Mailer: b4 0.15-dev 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" Use recommended values as per wa_14021694213 to compare with the calculated value and choose minimum of them. v2: corrected checkpatch warning and retain the restriction for min_hblank (Jani) v3: use calculated value to compare with recomended value and choose minimum of them (Imre) v4: As driver supported min bpc is 8, omit the condition check for bpc6 with ycbcr420. Added a note for the same (Imre) v5: Add a warn for the unexpected case of 6bpc + uhbr + ycbcr420 Bspec: 74379 Signed-off-by: Arun R Murthy --- Changes in v5: - EDITME: describe what is new in this series revision. - EDITME: use bulletpoints and terse descriptions. - Link to v4: https://lore.kernel.org/r/20250728-min_hblank-v4-1-b9d83bf03025@intel.com --- drivers/gpu/drm/i915/display/intel_dp.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 54d88f24b6893e1f8009f00dda87d8dae5dfc137..1cc19f3e7729c25d2066f42601a18bdfa03b2721 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -3182,7 +3182,26 @@ int intel_dp_compute_min_hblank(struct intel_crtc_state *crtc_state, */ min_hblank = min_hblank - 2; - min_hblank = min(10, min_hblank); + /* + * min_hblank formula is undergoing a change, to avoid underrun use the + * recomended value in spec to compare with the calculated one and use the + * minimum value + */ + if (intel_dp_is_uhbr(crtc_state)) { + /* + * Note: Driver doesn't support compressed bpp 6. + * Its unusual to have 6bpc with YCBCR420, for which the spec suggests + * a minimum hblank value of 2(Hence this condition is omitted). + */ + drm_WARN(display->drm, (crtc_state->dsc.compression_enable && + crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 && + crtc_state->dsc.compressed_bpp_x16 == 6), + "Unusual to have compressed bpp 6 with ycbcr420\n"); + min_hblank = min(3, min_hblank); + } else { + min_hblank = min(10, min_hblank); + } + crtc_state->min_hblank = min_hblank; return 0; --- base-commit: eb0c2b25072b5c56e8c41d7099050bf53bebaa14 change-id: 20250728-min_hblank-263ceb40508c Best regards, -- Arun R Murthy