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 E8DACD358C0 for ; Thu, 29 Jan 2026 06:29:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 33D3E10E002; Thu, 29 Jan 2026 06:29:33 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b="dHUiJQR5"; dkim-atps=neutral Received: from mail-wm1-f48.google.com (mail-wm1-f48.google.com [209.85.128.48]) by gabe.freedesktop.org (Postfix) with ESMTPS id 08D3810E002 for ; Thu, 29 Jan 2026 06:29:31 +0000 (UTC) Received: by mail-wm1-f48.google.com with SMTP id 5b1f17b1804b1-4806f9e61f9so2746185e9.1 for ; Wed, 28 Jan 2026 22:29:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1769668170; x=1770272970; darn=lists.freedesktop.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=puA+CnwxAlMqbOnhYN3pZRQlGRvX1b7vDRdIRgp2KfA=; b=dHUiJQR5x1lMzKKRfVGy+JWemZo8mzoAIJtLg44PaFiPf5GsW/6uu54IH9MNyhWEkV H/Ydic97UIkABG2fxqvSpQC1sOz0Dq+PFBTlBmFGvvXYaAjWW5Hf4VjlZLeQWvwcd+C7 CjMt+k3Kyxh/tWExKZ65gc5H4ehDnJ+lPIw88oh7nLtuM1jA3N6eUn1hIjVuAOGV2OhW Hoji7m1Vk6lDq8IpYyWlNTqmB9OMKTiAmhWFvR/AivVpHGipHcnvxlOFNhU9YVYyvC/6 +m5MdZxJFTS7KX1KUtyRa/+CFoNedztcf/llw206ix0k+K+CaAhRUbN6zguBouuSY3j4 OPJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769668170; x=1770272970; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=puA+CnwxAlMqbOnhYN3pZRQlGRvX1b7vDRdIRgp2KfA=; b=jNW0VTPb4X1qcuCQ+7sc8wA/B8fT1vH9CVeoPaiDsKYAWNEUfnBPjM5Aj0frLKQWHQ WZI3zM0dwxZ1vqsLrBO3H1sD9cErkZxh2rU2s+C4ueW6G3NEisGgC4VO8D8QGC8xxjYD HJIwMTydP7doCYha42lac5gxYMcy0rs7FkNgDXmydr+4/MumEwPCJlOYEbHXM8FLV5xD m5uzbLMm6OCYqVNzSviztbeYJB+BWAjkCSJcplR8rg3unKqFNRjaW/gqxhoF0KCZwJjX ra7VgRisFl3hlA/Xq4Ys6sAhi+w88IRBUManbI+mSdwjnAEKhyZrAMEh0wimc+d4tiN7 CyjQ== X-Forwarded-Encrypted: i=1; AJvYcCWOkZmkNBtnkhufGEk4uuFidRdSz5QAo9H/X+QK7ExM3VtbZIJor6cQ4pzsq3MrD/XfXi+1F9niYNU=@lists.freedesktop.org X-Gm-Message-State: AOJu0Yxb2ZkM8nVi1XG6J0Y1RIZZZdc2A76fhCbzQ73JoiQnc9RBDo51 tjtXfw2MY+OcIg/oSYouJDU8EgTLlJheP348nTmZ7nWsOcHzeCTV5AiRqcA6yK3v/Go= X-Gm-Gg: AZuq6aIRsLe77SO7X9HNHiXCyAzrK9r9CdOwmjPntftsNxsXu9FBO5Zblzx44GInAIc 6SEASYxMzqO3/KqcohgfPo6tWsgPzYTkPtuEMXrLGzr7roG1FuMqtqMnTy+xAgQhqMbLjNwCZ0E Oc+rQSIxyp9arBVVJQXLxcRLCsVo2Q3A33aqtKMC8moNV5u2Do1vsrQdF+KMGC5vs8hQrLKCFDR 4Kl5TkEgGI8rATeT65zeK5kxQWQ6AiLXHgY3aK2rkx8yGe02dyxDE2LpfMmAXnMLKEXyFK1ADoo 2vv9/SnRrTLf3/iav5vaodUS+oS86FQAHFnrYRd+pmB5WPcHxL9ZV29yYQ28I3gLozgs2ir81qz u27tGy8h7P26C5rfcz8UNtoraS0aLKzpWdyX/Yjt6VlPiQ43NtbFIDsjxWxF7YPu9PlnfF4Puab +FmNfgkIg48L5D0fxd X-Received: by 2002:a05:600c:468f:b0:477:a9e:859a with SMTP id 5b1f17b1804b1-48069c6948fmr105945805e9.22.1769668170238; Wed, 28 Jan 2026 22:29:30 -0800 (PST) Received: from localhost ([196.207.164.177]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4806cddffc0sm130968845e9.5.2026.01.28.22.29.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Jan 2026 22:29:29 -0800 (PST) Date: Thu, 29 Jan 2026 09:29:26 +0300 From: Dan Carpenter To: ChanSoo Shin , andy@kernel.org Cc: gregkh@linuxfoundation.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-staging@lists.linux.dev Subject: Re: [PATCH v5] fbtft: limit dirty rows based on damage range Message-ID: References: <20260128203938.962414-1-csshin9928@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260128203938.962414-1-csshin9928@gmail.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Jan 29, 2026 at 05:39:38AM +0900, ChanSoo Shin wrote: > Instead of marking the entire display as dirty, calculate the start > and end rows based on the damage offset and length and only mark the > affected rows dirty. This reduces unnecessary full framebuffer updates > for partial writes. > > Signed-off-by: ChanSoo Shin > --- TL/DR: I suck as a reviewer so I would be nervous to apply this without testing. Andy is an expert here and we trust him so if he's okay with it then great. Or if some other expert could sign off, but I don't know enough to sign off myself. The problem for me is how do I review something like this? Staging is a grab bag of different modules and I'm not an expert in any of the subsystems. Normally, it's easy to review staging patches because they are clean up work which does change how the code works so I just look for unintentional side effects. It's trickier to review a patch like this which changes runtime. If it were fixing a bug, then I could verify the bug is real and say well, "Maybe the fix is wrong, but we were going to corrupt memory anyway, so the worst case is that it is as bad as before. It can't make the problem worse." This is your first kernel patch. You don't work for a company that makes the hardware. You said earlier in a private email that this hasn't been tested. The patch looks reasonable to me, but it also looks simple. If it were that easy why didn't the original author do it? regards, dan carpenter