From patchwork Tue Feb 4 15:37:17 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 13959379 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 04642C02193 for ; Tue, 4 Feb 2025 15:37:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9760010E69B; Tue, 4 Feb 2025 15:37:25 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="cJU7OMHj"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1D51410E69B; Tue, 4 Feb 2025 15:37:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1738683444; x=1770219444; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=sdZcClBITbXtP7lcJhpf/sK2aHommAuD9xVTxI5M194=; b=cJU7OMHjVQj7ReKDLPWxNuMduXu34THxTk7OeU+UmsIAc7b+SxBoaio7 O/2WBsyT3tTN+G7xtdc17u+x2+mR647uDSC8zIUQRLHpyewi3ESSiHZRB 5SuBL+i6PJiESWbkrqJdUMHG95FVIROTNjAIDO0mFSDP2eu8IsWIkgMb/ oVFj3a/1pKg9x71SGSSOfkFsdLijgD2WBYdYv2JQZpsToFmf52Xso8cXm LIBZgTWGNsD/yKIZW88ggzCAeGrEiC2nRL92HBZRxtccILiM7g+IXYG8e aKYe0GraQD77j5/SGYPzDQThGrVGsE4bn3KDuZsqXeuicl0t+/ajk91eN A==; X-CSE-ConnectionGUID: lNaVSm2dQVm4wWvXDxJZ3g== X-CSE-MsgGUID: QeIuvy2DT9Sf8MQACHk/6A== X-IronPort-AV: E=McAfee;i="6700,10204,11336"; a="39118171" X-IronPort-AV: E=Sophos;i="6.13,258,1732608000"; d="scan'208";a="39118171" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2025 07:37:23 -0800 X-CSE-ConnectionGUID: xl5rmTd9RJG7RlYpMaOwyQ== X-CSE-MsgGUID: TbfJnzM0S0K0SLbsbu0K/Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,258,1732608000"; d="scan'208";a="110796295" Received: from dprybysh-mobl.ger.corp.intel.com (HELO localhost) ([10.245.246.139]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2025 07:37:21 -0800 From: Jani Nikula To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org Cc: jani.nikula@intel.com, Imre Deak Subject: [PATCH] drm/i915/mst: fix INT_MAX to .4 fixed point conversion mistake Date: Tue, 4 Feb 2025 17:37:17 +0200 Message-Id: <20250204153717.2996923-1-jani.nikula@intel.com> X-Mailer: git-send-email 2.39.5 MIME-Version: 1.0 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo 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" intel_dp_mtp_tu_compute_config() conversion to use .4 fixed point didn't take into account that intel_dp_mst_max_dpt_bpp() may return INT_MAX when the transport limitation is not relevant. Converting INT_MAX to .4 fixed point results in -1.0, which then gets used as if it were a real max BPP value: i915 0000:00:02.0: [drm:intel_dp_mtp_tu_compute_config [i915]] Limiting bpp to max DPT bpp (24.0000 -> -1.0000) i915 0000:00:02.0: [drm:intel_dp_mtp_tu_compute_config [i915]] Looking for slots in range min bpp 18.0000 max bpp -1.0000 Just return 0 for "no max DPT BPP", and handle it explicitly. Fixes: 67782bf6e8a6 ("drm/i915/mst: Convert intel_dp_mtp_tu_compute_config() to .4 format") Cc: Imre Deak Signed-off-by: Jani Nikula Reviewed-by: Imre Deak --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index b729e27cdde2..95abc6ea85eb 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -111,7 +111,7 @@ static int intel_dp_mst_max_dpt_bpp(const struct intel_crtc_state *crtc_state, &crtc_state->hw.adjusted_mode; if (!intel_dp_is_uhbr(crtc_state) || DISPLAY_VER(display) >= 20 || !dsc) - return INT_MAX; + return 0; /* * DSC->DPT interface width: @@ -248,7 +248,7 @@ int intel_dp_mtp_tu_compute_config(struct intel_dp *intel_dp, } max_dpt_bpp_x16 = fxp_q4_from_int(intel_dp_mst_max_dpt_bpp(crtc_state, dsc)); - if (max_bpp_x16 > max_dpt_bpp_x16) { + if (max_dpt_bpp_x16 && max_bpp_x16 > max_dpt_bpp_x16) { drm_dbg_kms(display->drm, "Limiting bpp to max DPT bpp (" FXP_Q4_FMT " -> " FXP_Q4_FMT ")\n", FXP_Q4_ARGS(max_bpp_x16), FXP_Q4_ARGS(max_dpt_bpp_x16)); max_bpp_x16 = max_dpt_bpp_x16;