From nobody Fri Apr 3 01:24:30 2026 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 F38A83DD515 for ; Wed, 25 Mar 2026 14:01:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774447318; cv=none; b=lj2WodvV8ANouyInjIdQ7z/3pKhvpxlINcsMcxabBuC6ueg6PXhRmgUEuvdoc8mxo5UqehUDSgBAtrOOFBA7ZeJn8BAetGAFqApOAk8/kwZUxDMBq5x+mtF3NS3fKjeAx4DH8WC++FOhNfQn+LN2rIauzBTbJyuHCgbx9YzSC4A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774447318; c=relaxed/simple; bh=qsLARDIVnkaD/ICi7soozFniWWJmCvAqHDdDTOWdWNc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=W94mb+LEVPkr8brTD1pOwAMFZj+5bmj+USt8ck11lahoLqMGQEwewm/TMI88D/SM6eUxOq+1jNnS7Ty6gEcC8vCOZBEQBqBmwVsMiDT8zzNCZ0v3A2z4wqUZXxN8SMRDa1KbjgVldbou2s7xlPmdWXjlfPLj9SG6w/lJzhdFKhE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=lF587bCn; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="lF587bCn" Received: from [127.0.1.1] (91-158-153-178.elisa-laajakaista.fi [91.158.153.178]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id DB3651862; Wed, 25 Mar 2026 15:00:33 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1774447234; bh=qsLARDIVnkaD/ICi7soozFniWWJmCvAqHDdDTOWdWNc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=lF587bCnjk96kRIOnhLuuZueHe6u03Vp48+mNFLsNW4Pn+IP+ZHuEXrXTPRHZ7+YO sVMWc/lOjpLOvYigVwDEMy0SL0MykDKv6vWKrevGybIK9X2lBY/QjMNpk41q9xBPjT LZuYpKDrbMbZPOmwB41f7K/QiJ3Q6ErMJV34RaKc= From: Tomi Valkeinen Date: Wed, 25 Mar 2026 16:01:24 +0200 Subject: [PATCH v9 01/11] drm/fourcc: Add warning for bad bpp Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260325-xilinx-formats-v9-1-d03b7e3752e4@ideasonboard.com> References: <20260325-xilinx-formats-v9-0-d03b7e3752e4@ideasonboard.com> In-Reply-To: <20260325-xilinx-formats-v9-0-d03b7e3752e4@ideasonboard.com> To: Vishal Sagar , Anatoliy Klymenko , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Laurent Pinchart , Michal Simek , Simon Ser Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Geert Uytterhoeven , Dmitry Baryshkov , Pekka Paalanen , Tomi Valkeinen X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=1792; i=tomi.valkeinen@ideasonboard.com; h=from:subject:message-id; bh=qsLARDIVnkaD/ICi7soozFniWWJmCvAqHDdDTOWdWNc=; b=owEBbQKS/ZANAwAIAfo9qoy8lh71AcsmYgBpw+rKDYNdViLCLpYqmZY0SWmqG5dqG7vwwbdHf xBeIPg+ZiCJAjMEAAEIAB0WIQTEOAw+ll79gQef86f6PaqMvJYe9QUCacPqygAKCRD6PaqMvJYe 9b6yEACZbXoKPDiWE2N5P6E9h8U/nh2IAvHlKdisK3dSbhI2w8QJyHDIZ35PsOGhEmhynk0rSEC SXYP4gXR+V7WlAnsroPmcagxUtt7WZGZXoRWCkWxd8YgN+BX1ETCWADTXvry4oYUI7tJV2Hf/QD 4KJ9fwZcTFHZVqDq0EQjHmMv7SplpqL0RJwYVAxqgquFRz0FJpj1qH0+5qlOKa24psIzq6ICCFn TpAlP2/wenQ/0cxFdZEIa+wwxKQcWid280+84DCs6vsG1KT0OuvFsh46TPUGxIA5vC4FIjgifJJ /hlaA1gtlFYC7JSui0UBOKfhNYH/vkF895MuKub+jpODFhYg74i71rSdLHYS0S8UWSRFNxBnwA9 XE1W38JfDpDJ3J+UzOZC3M0FJweCx29QWhNLik9+S5P0E4yrUk8xLef2CNdQZtbHsF/WCN7JDOh HL9/CUpJz7Xv9PgLdzPeIjUtEWcCZw3gLqJrTyKvrTUPef2/N1bifxV/nVg/wSf6F28nZSR1TCb ygayljh2ewhRZfynm1FbwB2kiSaCgr2zCnK6xdi0S+ECp1odkv+62iEqYsWg+J9kwB31hcuoA52 fW0FJIuUMBYfhqQQY5RfqMfFTN2vmJ82TwV8nKHsZtdK5psK0Raza5Cf0EikElS9tonfTihy2KU QhlNqqK4aCPb+sg== X-Developer-Key: i=tomi.valkeinen@ideasonboard.com; a=openpgp; fpr=C4380C3E965EFD81079FF3A7FA3DAA8CBC961EF5 drm_format_info_bpp() cannot be used for formats which do not have an integer bits-per-pixel in a pixel block. E.g. DRM_FORMAT_P030's plane 0 has three 10-bit pixels (Y components), and two padding bits, in a 4 byte block. That is 10.666... bits per pixel when considering the whole 4 byte block, which is what drm_format_info_bpp() does. Thus a driver that supports such formats cannot use drm_format_info_bpp(), It is a driver bug if this happens, but so handle wrong calls by printing a warning and returning 0. Reviewed-by: Laurent Pinchart Reviewed-by: Dmitry Baryshkov Signed-off-by: Tomi Valkeinen --- drivers/gpu/drm/drm_fourcc.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index e0d533611040..e662aea9d105 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -491,12 +491,20 @@ EXPORT_SYMBOL(drm_format_info_block_height); */ unsigned int drm_format_info_bpp(const struct drm_format_info *info, int p= lane) { + unsigned int block_size; + if (!info || plane < 0 || plane >=3D info->num_planes) return 0; =20 - return info->char_per_block[plane] * 8 / - (drm_format_info_block_width(info, plane) * - drm_format_info_block_height(info, plane)); + block_size =3D drm_format_info_block_width(info, plane) * + drm_format_info_block_height(info, plane); + + if (info->char_per_block[plane] * 8 % block_size) { + pr_warn("unable to return an integer bpp\n"); + return 0; + } + + return info->char_per_block[plane] * 8 / block_size; } EXPORT_SYMBOL(drm_format_info_bpp); =20 --=20 2.43.0