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 A941ACCD184 for ; Tue, 21 Oct 2025 07:42:57 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1A6C010E57E; Tue, 21 Oct 2025 07:42:57 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="Jkz5cwDI"; dkim-atps=neutral Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2A6C310E57E for ; Tue, 21 Oct 2025 07:42:56 +0000 (UTC) Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-b3f5a6e114dso94901866b.0 for ; Tue, 21 Oct 2025 00:42:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1761032575; x=1761637375; darn=lists.freedesktop.org; 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=GStPgF6qWg8eBpq7k/CjdOQ6h0CGmfUgYnZon0KO2vw=; b=Jkz5cwDIxV+dWMNvCwAvHQSKsIxzqsW/JDwfS7m1Lq6QaUCUFn0aNfV1A+h5i2IrJf fNEr8SVxzw4rZ+PRhNAlJ6UhDDY8BO7UQ7ABZCRfrrkmMO7ZDtOF9iAbke3zCYw1ry8I +dlkQp8ZkREWTwhD8DX/oaaHZIAlLfumNEhODe+gYje1JGpRcgk2AmOMm+T5YnyCCe3U 9M5KhwlFFqNh0OJaXgyAp+Kyx1hj+YRmuYffrWTlekHPf2eOoL7KIiPrGZZSDgeM5CRD oRne0Crli0SG6s8IvqU1Jd1GbnHaWHhRNInDFnnmc61OMwBo4BxDadCTWuM3g9R/PWUq 7faQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761032575; x=1761637375; 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=GStPgF6qWg8eBpq7k/CjdOQ6h0CGmfUgYnZon0KO2vw=; b=QD7B10JD2CbqW3E8BpYlqIzyeR1FH3wlgOGOo7H6+boY4HSBNWYd1u/91ZmmOEt9zn VRc0QPnIvNQslc9Lo8rxRi2De2jpsuOShprR3atTrwPBS1ZJ8lW/a64YnkYH9zrM14xz A+2CEHMRIShxBroZYpaeuEYkLEVDOvSOlnHYfFIOuzOSaXWA7kFDNvyTATN3DxTPdAdm U20gEe5BbjthL+Ks2t4CabyB5SuNUqP6uBPqe2fi30Wu5o4lqtA5lf+YgDEEeidGGTpy ZDDW6VVWIP9BtWpuxu1UtUypE1bXQxr9V36QOMXVm3YZ/RT6wokZlnSINQE4Z0o3ump0 BZyg== X-Gm-Message-State: AOJu0Ywywus0CXR5mYd+J8JQ1DjW+hyew24CofMhDUEKQnPn4G2A5KWl SGOSoQFAPu9thSXj6MhRPMaLDwqczkanU8p6K0dN6VNrjBiaMHqADnYd X-Gm-Gg: ASbGncvoj2rGNBqWCzNE7gtvGkUNNINZV4t7L+FpsVTHdgl3YGjO5zjQbaT803RljcL 0pGfe5lrxBYRhqVyilU2kKHVIfjbmXrERRMg4hz4+ZgC3UKtjvK33gULy4Y6C3Q+yWL6PRbZhgS FoGm4lBEp1d+7c/Lkflw8ZNH4pxUb/vh6ii7U9kklwdbs0rcNZ+2pileREApqWB2X/5fr2d800b LuhtDgNhg0p2gA/jdeXX0LXx/3JqwE5ntYy2221gnTfap4uYI+f13QAzlY0GvGdu6gGy/tD+Rot 6AuJc8HItztIOuv5KiVPFV6aotFu+0nG1m8IUJZlTn5eE/8Ba9F9EhVwhqlv5JKK3xl5F2HxKEC PAL5kU5JZD0pJzYCEZ1StOR17NPdeIxGXbCwjpfsEC09MjhLJ3ulunmujXwu/y+6wNkT8lmU4ou 89WDPe3sEv20B39hS/RT13IOsxqfF/ X-Google-Smtp-Source: AGHT+IGTAHitbAGYUoiDBb3JjyGZ6zbzSc2aytK1cYPhymZfc5cQ/shi+4Gz6sE1cziBWlkHoCqTpg== X-Received: by 2002:a17:907:6ea3:b0:b65:c8b8:144f with SMTP id a640c23a62f3a-b6c793063bbmr164905566b.6.1761032574440; Tue, 21 Oct 2025 00:42:54 -0700 (PDT) Received: from [192.168.1.105] ([165.50.73.64]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b65e7da25c9sm1018929566b.11.2025.10.21.00.42.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Oct 2025 00:42:54 -0700 (PDT) Message-ID: Date: Tue, 21 Oct 2025 09:42:46 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/tiny: Refactor framebuffer's size calculation To: Thomas Zimmermann , lanzano.alex@gmail.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, airlied@gmail.com, simona@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, david.hunter.linux@gmail.com, khalid@kernel.org, linux-kernel-mentees@lists.linuxfoundation.org References: <20251020115803.192572-1-mehdi.benhadjkhelifa@gmail.com> <1de3112b-6349-46d8-b90b-69d0849c7659@suse.de> Content-Language: en-US From: Mehdi Ben Hadj Khelifa In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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 10/21/25 7:57 AM, Thomas Zimmermann wrote: > > > Am 21.10.25 um 08:51 schrieb Thomas Zimmermann: >> Hi >> >> Am 20.10.25 um 13:57 schrieb Mehdi Ben Hadj Khelifa: >>> Use drm_format_info_min_pitch() to calculate the framebuffer line pitch >>> instead of directly multiplying width and height. This aligns with DRM >>> helpers for determining per-line byte size and avoids manual assumptions >>> about bytes per pixel. >>> >>> Suggested-by: Thomas Zimmermann >>> Signed-off-by: Mehdi Ben Hadj Khelifa >>> --- >>>   drivers/gpu/drm/tiny/repaper.c | 6 +++++- >>>   1 file changed, 5 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/ >>> repaper.c >>> index 4824f863fdba..aeff49bc6ba7 100644 >>> --- a/drivers/gpu/drm/tiny/repaper.c >>> +++ b/drivers/gpu/drm/tiny/repaper.c >>> @@ -517,6 +517,8 @@ static int repaper_fb_dirty(struct >>> drm_framebuffer *fb, const struct iosys_map * >>>       unsigned int dst_pitch = 0; >>>       struct iosys_map dst; >>>       struct drm_rect clip; >>> +    const struct drm_format_info *info = fb->format; >> >> This is the wrong format. You're allocating the output buffer here, >> but you're using the input format. IIUC the output format is >> DRM_FORMAT_R1. The input is _XRGB8888. >> >> Best regards >> Thomas >> >>> +    size_t pitch; >>>       int idx, ret = 0; >>>       u8 *buf = NULL; >>>   @@ -534,7 +536,9 @@ static int repaper_fb_dirty(struct >>> drm_framebuffer *fb, const struct iosys_map * >>>       DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, >>>             epd->factored_stage_time); >>>   -    buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL); >>> +    pitch = drm_format_info_min_pitch(info, 0, fb->width); >>> + >>> +    buf = kmalloc_array(fb->height, pitch, GFP_KERNEL); > > And TBH I'm not sure if we should really convert this call. It's not an > array in the sense of that API. > > Good candidates look like 'kmalloc(count * sizeof( variable>))' > I will leave kmalloc in v3. Do you want me to send deep testing information on this patch? BR, Mehdi>>>       if (!buf) { >>>           ret = -ENOMEM; >>>           goto out_exit; >> >