From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 41C4338885B for ; Tue, 10 Feb 2026 17:24:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770744293; cv=pass; b=Gtxu2nmBGHeTaADHqFp1JtzlyUOujF6yiWRawMgdTR0vS2q/9m5ufW3qXxsHW/UUoQgGMsYbzBi/snaBsbC4ZfYTCzOQauo/MFF4+uDV0Kaxi8/u4LE+Ua5TYvgVLYQ/Tuf+vM0bSiuwa4srMJQbhjh43k1QVfecuEjqNufVxA8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770744293; c=relaxed/simple; bh=ejhKE8Ob0KzBzXjCuRLT+b0LJ+96MbII/Mc2z+KEdK4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=eHlAFAsWSA+JZjud44zbcLEhWg9ZUhXJbYVaONgw8FQo93Y45NWleFhL4fn5mtWqbJaWetZo4KGEZrOFF22VzN+LtkB5CC77VlZGkRdqjvINAB5HZ97sscWim5bJC6PhgIfSNQL5CCa9k7iwFA+AGoiV+7kipSsLrOS5yACPrUc= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=ariel.dalessandro@collabora.com header.b=hcKU/u3C; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=ariel.dalessandro@collabora.com header.b="hcKU/u3C" ARC-Seal: i=1; a=rsa-sha256; t=1770744263; cv=none; d=zohomail.com; s=zohoarc; b=bbdJgHxhb0qfTazCwFrPx9bVeGQqzGN+B2zNunthjMrq2y8QvNwu71y0OsczK3JyqRYP4aP7IblMqpm8BcA3wBwLMqZTIpGqUJH1Atzi/PL0qgRyqQs8MaXyImxQNzSIDSgQRIlvu9veK6n8v/UyMAcbEcJC59N5XwRJKCwFxAQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1770744263; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=2SVhTKI6jNUmvhweiBSHXKX4xnnqxteHj08x/32q7JI=; b=KCmfVDX5L4h5xR4P75o8+djnOZ2GJ/VB5EN1fPXax/O3u0iQV5LqapbrcgesNSbjt6W4msCjW7duYLxD2LmCUTH5f3o+m2GRYbWYRm/BagJroLQGXLrwW5n8+miykkqdr+2qkPJ2kKi8B7ZwlmPUHIArr1+F+HX6iEJ1uVan8zA= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=ariel.dalessandro@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1770744263; s=zohomail; d=collabora.com; i=ariel.dalessandro@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=2SVhTKI6jNUmvhweiBSHXKX4xnnqxteHj08x/32q7JI=; b=hcKU/u3Cu1sBRH53DO5YRoAp34aSpsMhvqSV5/xGYT4m2xGXAeTPDwbAnvi8CoEv vBPEcvSizkZTj6vBuII4JQDMw+2VbNf9jbMGn371TSVIME9aEAcDydjeVMQrtBykXuy swu6Td0Nd7/eyLl+7W2MOBKkHDykgNDHbGyX4Z3g= Received: by mx.zohomail.com with SMTPS id 1770744262665417.3252309425685; Tue, 10 Feb 2026 09:24:22 -0800 (PST) Message-ID: <58373d82-d238-4302-b72a-3625b153bd9e@collabora.com> Date: Tue, 10 Feb 2026 14:24:15 -0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/vkms: Fix bad matrix offset component multiplication To: Louis Chauvet , Haneen Mohammed , Simona Vetter , Melissa Wen , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, nfraprado@collabora.com, pekka.paalanen@collabora.com, daniels@collabora.com, kernel@collabora.com References: <20251223-vkms-composer-fix-matrix-v1-1-10a979e06209@collabora.com> <28d9f246-8952-4f03-94bc-60eadca78c2f@bootlin.com> Content-Language: en-US From: Ariel D'Alessandro In-Reply-To: <28d9f246-8952-4f03-94bc-60eadca78c2f@bootlin.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ZohoMailClient: External Hi Louis, Sorry for the delay. On 12/29/25 6:33 AM, Louis Chauvet wrote: > > > On 12/23/25 18:26, Ariel D'Alessandro wrote: >> Pixels values are packed as 16-bit UNORM values, so the matrix offset >> components must be multiplied properly by the idempotent element -i.e. >> number 1 encoded as 16-bit UNORM-. >> >> Signed-off-by: Ariel D'Alessandro > > Hi, > > Thanks for this patch! > > How did you catch the issue? If you have an example of failing color > conversion, can you add a test case in vkms_color_test? I found it while working on this IGT tools patch series [0], this patch in particular [1]. I've just added the related kunit test, so I'll send it as a v2 patchset. [0] https://lore.kernel.org/igt-dev/20251223-post-blend-colorops-v2-0-f40aca9795bd@collabora.com/ [1] https://lore.kernel.org/igt-dev/20251223-post-blend-colorops-v2-7-f40aca9795bd@collabora.com/ Regards, -- Ariel D'Alessandro Software Engineer Collabora Ltd. Platinum Building, St John's Innovation Park, Cambridge CB4 0DS, UK Registered in England & Wales, no. 5513718