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 01A9ECCFA19 for ; Wed, 5 Nov 2025 12:22:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9B8CD10E721; Wed, 5 Nov 2025 12:22:54 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="VqyBvSrX"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id 12B0810E723; Wed, 5 Nov 2025 12:22:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1762345374; x=1793881374; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=q/Pqen8C/RbXIRAfOIuqqKLA6HwuAxYmOfmzmTcVXSY=; b=VqyBvSrXbVoCTzqFAqRmMskVxRXKEuncUWizVkoVJyWXEf2BQsJOZffl t5wNx8WhhSJfrnPQHfDr9JjdIRqLpjiMXULcxr8GXdX6eQGG+e9SeZdc7 EYq9Nf9Eqmgb1yiIkyK36MvdKsA22I9KtX4JIuVuNrzAJ+FEdIDjYoWlB Hx/4D9rNzy08dSIcJhvsbyx56KZBriEqs8FrlAndXD8+nkGuVzxAMHl6B LjOsjSAVMeulEIQUPV0L5Q3gMhOi/1LjHOvCrYywf8/7h9TArTNCj85cU lydODniwfko4uT8OwZ/MtbS8lf//oCeoP38/uHGgu2EaHnarhxXhs1CZK Q==; X-CSE-ConnectionGUID: P27iwr+qRmCc96+VFi6LoA== X-CSE-MsgGUID: BPnbbOwRTQGlDClhyYlIUg== X-IronPort-AV: E=McAfee;i="6800,10657,11603"; a="68317532" X-IronPort-AV: E=Sophos;i="6.19,281,1754982000"; d="scan'208";a="68317532" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Nov 2025 04:22:54 -0800 X-CSE-ConnectionGUID: gZzN+wQdQryz8sHqL2LfJw== X-CSE-MsgGUID: hHhIT9xlSs2m033/BsZtKw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,281,1754982000"; d="scan'208";a="187740256" Received: from cfl-desktop.iind.intel.com ([10.190.239.20]) by fmviesa008.fm.intel.com with ESMTP; 05 Nov 2025 04:22:49 -0800 From: Uma Shankar To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: chaitanya.kumar.borah@intel.com, ville.syrjala@linux.intel.com, pekka.paalanen@collabora.com, contact@emersion.fr, harry.wentland@amd.com, mwen@igalia.com, jadahl@redhat.com, sebastian.wick@redhat.com, shashank.sharma@amd.com, swati2.sharma@intel.com, alex.hung@amd.com, jani.nikula@intel.com, Uma Shankar Subject: [v6 07/16] drm/i915/color: Preserve sign bit when int_bits is Zero Date: Wed, 5 Nov 2025 18:04:03 +0530 Message-ID: <20251105123413.2671075-8-uma.shankar@intel.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20251105123413.2671075-1-uma.shankar@intel.com> References: <20251105123413.2671075-1-uma.shankar@intel.com> 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" From: Chaitanya Kumar Borah When int_bits == 0, we lose the sign bit when we do the range check and apply the mask. Fix this by ensuring a minimum of one integer bit, which guarantees space for the sign bit in fully fractional representations (e.g. S0.12) Signed-off-by: Chaitanya Kumar Borah Signed-off-by: Uma Shankar --- drivers/gpu/drm/i915/display/intel_color.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c index a45d348c9851..aef25cb63457 100644 --- a/drivers/gpu/drm/i915/display/intel_color.c +++ b/drivers/gpu/drm/i915/display/intel_color.c @@ -613,6 +613,8 @@ static u16 ctm_to_twos_complement(u64 coeff, int int_bits, int frac_bits) if (CTM_COEFF_NEGATIVE(coeff)) c = -c; + int_bits = max(int_bits, 1); + c = clamp(c, -(s64)BIT(int_bits + frac_bits - 1), (s64)(BIT(int_bits + frac_bits - 1) - 1)); -- 2.50.1