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 7D8BEC433F5 for ; Sun, 9 Oct 2022 18:52:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230212AbiJISwp (ORCPT ); Sun, 9 Oct 2022 14:52:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230027AbiJISwo (ORCPT ); Sun, 9 Oct 2022 14:52:44 -0400 Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E72C829C98 for ; Sun, 9 Oct 2022 11:52:42 -0700 (PDT) Received: by mail-lf1-x134.google.com with SMTP id f37so13807812lfv.8 for ; Sun, 09 Oct 2022 11:52:42 -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:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=pIjqS6gdtTRggpFmsM12g61XiUJqlB1w3Lk7PGDiY4k=; b=SQcpo++Aix4dizmqjgzZCFPDhj3ziY+qCd0ihacLAwRIKs5cxTL6R6IFiwqleLXyfT ZoaANhOY75dDQTTP2FZZCS7I5A/N/GtWVvDdwEkh9uuwSincRBNQ+SsgPjTAGuMjBjHs AuVmzhD3FwSbvERNUzd5SnRMVgElcZ3jOC4P5VcqD2K0iRVGb5DGBwXvBJOhQWF6JS+N JpuXjzFv1bwvUq8YqN2QWFG+GH7B+m0P1kGqFm5EnakO6jP8tBTwh6fVS/m43l8rkWWh OdpOwxcAdLo79dS/S95QLmIRXlTtpI4eWS/X4mi2waKPAt2/wdAllMAZQZCp7ax7Gvnp rBTw== 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:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=pIjqS6gdtTRggpFmsM12g61XiUJqlB1w3Lk7PGDiY4k=; b=lRIO0SxzMmouZH2wJJIDxt91xT0xS1vOGBTpJevfqwWU42jBFosziPH0hHKvBWVyg3 rVPNA7+LdmCAlTvEshm82kAQbTzJPWrkNbndLTYifk2K1HOa/FMM2juookE0nOuHiloo lhdhp2QtxnSoB8e42L9wlExOG1XQlEEOfRcwkQldSuo4CYDezKx2GRxk+tsahY/ysYLG xMXmpu7iZWRYEPV5doeCGl0RfhZnwOc9+jcE/hjgh8YgncJd7M/Q784rVjexJ3NlbwN/ 4KsSnTLNl0L3Ar++GY6ZwE2RsOQ6qzF2TGIeHM610q9MtXc24bGlEm2kwkiygQm46+av zMKw== X-Gm-Message-State: ACrzQf1uXcE4G5Bk9PT0mNj2gPFkW7ZSR1Hwn9q2pflQPpRWMCH7p5Yb oTnGJfX/nrfKx94FiKqY4xIduA== X-Google-Smtp-Source: AMsMyM796VexOVGOSvF6wQDt52LNKPg+357XUoXWAH85pGOFs1V4DM5iIN+W/mnB4ZIqI0uNLyioQw== X-Received: by 2002:ac2:5931:0:b0:4a2:be5d:edac with SMTP id v17-20020ac25931000000b004a2be5dedacmr3273463lfi.332.1665341561243; Sun, 09 Oct 2022 11:52:41 -0700 (PDT) Received: from [192.168.1.211] ([37.153.55.125]) by smtp.gmail.com with ESMTPSA id q14-20020a056512210e00b00485caa0f5dfsm1114474lfr.44.2022.10.09.11.52.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 09 Oct 2022 11:52:40 -0700 (PDT) Message-ID: <3f5cb79b-f745-8b7b-bacd-f9ea2988baea@linaro.org> Date: Sun, 9 Oct 2022 21:52:40 +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 01/10] drm/msm/dsi: Remove useless math in DSC calculations To: Marijn Suijten , phone-devel@vger.kernel.org, Rob Clark , Abhinav Kumar , Vinod Koul Cc: ~postmarketos/upstreaming@lists.sr.ht, AngeloGioacchino Del Regno , Konrad Dybcio , Martin Botka , Jami Kettunen , Sean Paul , David Airlie , Daniel Vetter , 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> <20221009184824.457416-2-marijn.suijten@somainline.org> Content-Language: en-GB From: Dmitry Baryshkov In-Reply-To: <20221009184824.457416-2-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 21:48, Marijn Suijten wrote: > Multiplying a value by 2 and adding 1 to it always results in a value > that is uneven, and that 1 gets truncated immediately when performing > integer division by 2 again. There is no "rounding" possible here. > > After that target_bpp_x16 is used to store a multiplication of > bits_per_pixel by 16 which is only ever read to immediately be divided > by 16 again, and is elided in much the same way. > > Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") > Signed-off-by: Marijn Suijten > Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov -- With best wishes Dmitry