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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A977C433F5 for ; Sun, 9 Oct 2022 19:14:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229691AbiJITOV (ORCPT ); Sun, 9 Oct 2022 15:14:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230206AbiJITOU (ORCPT ); Sun, 9 Oct 2022 15:14:20 -0400 Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBED91F9FE for ; Sun, 9 Oct 2022 12:14:18 -0700 (PDT) Received: by mail-lj1-x22f.google.com with SMTP id z15so3399192ljq.11 for ; Sun, 09 Oct 2022 12:14:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=eLmKWVTMUSHqEP9DIVkRM+ZnS7XRFcavZfbEdhp8mMc=; b=D3znIKzXKwQaxB7Ox3lpizhW7NS6r19zfvTiJftlw02OF9QCPjt9kbEIllwQSDwAZm bbQd6AGAx4o2TTHo7hE884uCEcGqpp6G4Ny7jvmIBpXYmT2rwz0rUyxYHHYb6xXZLDHc E/DV8n9stU9dLyYaAgvDlJFsbnUibYlnZ3lQiZYIXY6gD7JTWs4L3E2890nEcjUZGl/p uegdz2Z11CjMAJ7dwVkfNE9BlNRrCClWYLW6o+2UaccXyf4zJIrbSLQt8/GNaAY2oQap k8xV2eGWsUXni6SEBMXVz/OEX8Xxc0HYD+ZcLhdkj1uBQdTp3VrXeNoO6jBsfp9PWNDD kUfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=eLmKWVTMUSHqEP9DIVkRM+ZnS7XRFcavZfbEdhp8mMc=; b=zDgCdMtlqCwCp7Iu0oFoc/r3RMzG84gLWVUn7rQtpxwQrVcGnWB4JJW7uqUxuDskvN n2colHpaHtKE6UzyLDrSgUGLbx789XDNjimyuGU6mFbJtKezJl+c/bM3Qrv+uYRD42qo /t7VxfPqjI/N9GxwpCVogoT/2wGOI1sFAY8TomvweUc+MUlWI+Xq0nlu5hwgvmqdFzYO E+aW3lrFfW6Yr6tP9SaOR7l716keUwdeAl+QFjmwVUmDxV6rxqA9CxUrHSRRrtMMy1vB GYPCPdqFSiLiIKyzcHDUZ9mCQbBwOltQnZDCKEo4XeBvzyhf3yat7ry+reI+QvcH+Stk nNOw== X-Gm-Message-State: ACrzQf0B6yRidOfWyHmpIK0FBciOExLpOhqrYRiFLIMVaGQWBIAKHYFu krvZKa5Ec7DgR0jzjR9ae3teqg== X-Google-Smtp-Source: AMsMyM4a9wjRAHNMLggg3ZrR/45pdnYmZIpeoXCdgpM946/5KOUGeLQrsUAwlMweZbXSn4hMmZKK0g== X-Received: by 2002:a2e:a54b:0:b0:26c:72ed:b758 with SMTP id e11-20020a2ea54b000000b0026c72edb758mr5535281ljn.245.1665342857092; Sun, 09 Oct 2022 12:14:17 -0700 (PDT) Received: from [192.168.1.211] ([37.153.55.125]) by smtp.gmail.com with ESMTPSA id d14-20020a056512368e00b004946c3cf53fsm1117170lfs.59.2022.10.09.12.14.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 09 Oct 2022 12:14:16 -0700 (PDT) Message-ID: <408bf6a2-47fe-3eaf-7235-578d33a576c9@linaro.org> Date: Sun, 9 Oct 2022 22:14:16 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 Subject: Re: [PATCH v3 10/10] drm/msm/dsi: Prevent signed BPG offsets from bleeding into adjacent bits Content-Language: en-GB To: Marijn Suijten , phone-devel@vger.kernel.org Cc: ~postmarketos/upstreaming@lists.sr.ht, AngeloGioacchino Del Regno , Konrad Dybcio , Martin Botka , Jami Kettunen , Rob Clark , Abhinav Kumar , Sean Paul , David Airlie , Daniel Vetter , Vinod Koul , Douglas Anderson , Vladimir Lypak , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20221009184824.457416-1-marijn.suijten@somainline.org> <20221009185316.462522-3-marijn.suijten@somainline.org> From: Dmitry Baryshkov In-Reply-To: <20221009185316.462522-3-marijn.suijten@somainline.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 09/10/2022 21:53, Marijn Suijten wrote: > The bpg_offset array contains negative BPG offsets which fill the full 8 > bits of a char thanks to two's complement: this however results in those > bits bleeding into the next field when the value is packed into DSC PPS > by the drm_dsc_helper function, which only expects range_bpg_offset to > contain 6-bit wide values. As a consequence random slices appear > corrupted on-screen (tested on a Sony Tama Akatsuki device with sdm845). > > Use AND operators to limit these two's complement values to 6 bits, > similar to the AMD and i915 drivers. > > Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") > Signed-off-by: Marijn Suijten Reviewed-by: Dmitry Baryshkov Side note: the DSC params tables are more or less common between amd, i916 and msm drivers. It might be worth moving them to the DSC helpers from the individual drivers. This would mean such masks handling can go into the helper too. -- With best wishes Dmitry