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 58875FCB602 for ; Sun, 8 Mar 2026 14:13:47 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3A84410E431; Sun, 8 Mar 2026 14:13:31 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="X09NVS21"; dkim-atps=neutral Received: from mail-yw1-f173.google.com (mail-yw1-f173.google.com [209.85.128.173]) by gabe.freedesktop.org (Postfix) with ESMTPS id AFE2410E012 for ; Sat, 7 Mar 2026 03:33:07 +0000 (UTC) Received: by mail-yw1-f173.google.com with SMTP id 00721157ae682-79801df3e21so90626977b3.2 for ; Fri, 06 Mar 2026 19:33:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1772854386; x=1773459186; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=/NIaTR733CEI10YxzEjaU+igMogbfaVYBZNgtGsYrGs=; b=X09NVS21bXVxaNDknlxyszZj9lWTlGgSYIciHl86zEynC4NCX/5W1SdAOFHBUOYnTH dEIMqtd6SVFbxKpJE8tjaMxWV6g6BT3B9OpUPZf00DTLx1dbRdpS00uXdqtkIgIW4qHl zzOi341m7jME6Xz6Rr2mBVcbWgbh5T08Gat0bRVEicWVjtl9hTc1VT6kLiHsB8wby6pn r6jMykHnNdJjI8I5J+lUdNLJ5oN/FZQrCxV3LXp2kYu8Hpp4XUXlHBNWIBJTmZOhJGLA 6wvvXKbhXH2DteTHtAuIDnt37+sOFJkimmyE77lz4ug/8nnif2re7Jb95VdA4tZszbcP RDtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772854386; x=1773459186; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/NIaTR733CEI10YxzEjaU+igMogbfaVYBZNgtGsYrGs=; b=cmHaUJlislbr3aGbrdXLzIpuXgV7GYUUYm8dDTJmEkBr+Djw3Zq6Jb5g7Bbr8KLLza 3ZxRJmjFTjquTq0F2AB/tRsjcL9insY/CG0gogEzzATD7n9pIq751aYnNIUIoQQ5FtPE egg8OT4MAV/D6NgiV/l3IUkTVTiRYSs7IL0fmzbZvD6dfw2w/JtelKDULzv/xEyVa2cN ZgzDoTIUpvFHHobk8OY4QEsXa9cnuPrIcx80oJcm+K/sRfMkYEPuGgDQx+s71u985kU5 iDjv6lq2E/tgG3E5GZF+ecHCX9aSGN0KBP6iaR4T6jTg/DCwZcfaSHu5bJWbGT0y4bS3 SjTA== X-Forwarded-Encrypted: i=1; AJvYcCXbB2tP5563BuUzzI1+H3cY5lmt8dUnqyBfGHOlU5mJ9XRHtIIESnk7hZUlKNdwkgIabnRqmTrkWoY=@lists.freedesktop.org X-Gm-Message-State: AOJu0YzWR7ovfhfhmfoE1oudzqL6bbR4+q96t0oRBvOsi/ETqpiX/GdJ hzfdzorrQHpQpvuLhKexU+2fotzR6Q3uw3o+EhtQPg4xx+rOgIDrNLGi X-Gm-Gg: ATEYQzyjQwzTOwt+DXt6pu0lhsdGCEHP4ccqXpAXlS7SPuRiGaF58Y7Y97BBFPSPv/u AMbCdwgPsJPUW/EAGTaxHyhaE8FmL+gk8wPLzcswiYJTy7dFLLPAFvop3q14QbX5V+mmD6AVp53 CnsJGfCNRW6+pR2gFvfCdFQmR1N7QIeRYBncSa6bJz/sQrV5ZxRDuR+9m2Y1hMEtbnoUN6jvx57 ULAL0+QVbC2tfXpDGB+WS4nDZ2qu8Cc2LcUU8ypp6wij61FTOO8gSusILY/MIHAJU1YHfEaKnzh 4CNCRf+o+RD+HGwc1opO1Vxmvxdu6vW8yrrxoHUnOUigd+0kvH1P8A3M+s8A2f2NzUjTd2pAQT1 Kwi1136u5oHZ6he5jZn00mep+sYTZqClmnXJEHABSZ68mz6E1wrYryh3GHYCDiPg7cL5h6vJXxo mQVATClw98gae6MZ2JhFvQcfU0DndzwZVFiJtfQ27aoCygXSmJyGCb18483qDwkYPiAXrXgNZpH 0GlhDYN8WVMTiwrP1g8R8xJ X-Received: by 2002:a05:690c:ed5:b0:798:578c:2ad7 with SMTP id 00721157ae682-798dd756781mr41072307b3.39.1772854386380; Fri, 06 Mar 2026 19:33:06 -0800 (PST) Received: from tux ([2601:7c0:c37c:4c00::5585]) by smtp.gmail.com with ESMTPSA id 00721157ae682-798dee4a70bsm15274827b3.32.2026.03.06.19.33.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Mar 2026 19:33:06 -0800 (PST) From: Ethan Tidmore To: Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Marek Vasut , Joseph Guo , Ethan Tidmore , kernel test robot Subject: [PATCH] drm/bridge: waveshare-dsi: Fix signedness bug Date: Fri, 6 Mar 2026 21:32:45 -0600 Message-ID: <20260307033245.71666-1-ethantidmore06@gmail.com> X-Mailer: git-send-email 2.53.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Sun, 08 Mar 2026 14:13:21 +0000 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" The function drm_of_get_data_lanes_count_ep() returns negative error codes and dsi->lanes is an unsigned integer, so the check (dsi->lanes < 0) is always impossible. Make the return value of drm_of_get_data_lanes_count_ep() be assigned to ret, check for error, and then assign dsi->lanes to ret. Detected by Smatch: drivers/gpu/drm/bridge/waveshare-dsi.c:70 ws_bridge_attach_dsi() warn: unsigned 'dsi->lanes' is never less than zero. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202603060341.hNj0pl9L-lkp@intel.com/ Fixes: fca11428425e9 ("drm/bridge: waveshare-dsi: Add support for 1..4 DSI data lanes") Signed-off-by: Ethan Tidmore --- drivers/gpu/drm/bridge/waveshare-dsi.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/waveshare-dsi.c b/drivers/gpu/drm/bridge/waveshare-dsi.c index 0497c7ecbc7a..32d40414adb9 100644 --- a/drivers/gpu/drm/bridge/waveshare-dsi.c +++ b/drivers/gpu/drm/bridge/waveshare-dsi.c @@ -66,11 +66,13 @@ static int ws_bridge_attach_dsi(struct ws_bridge *ws) dsi->mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO | MIPI_DSI_CLOCK_NON_CONTINUOUS; dsi->format = MIPI_DSI_FMT_RGB888; - dsi->lanes = drm_of_get_data_lanes_count_ep(dev->of_node, 0, 0, 1, 4); - if (dsi->lanes < 0) { + ret = drm_of_get_data_lanes_count_ep(dev->of_node, 0, 0, 1, 4); + if (ret < 0) { dev_warn(dev, "Invalid or missing DSI lane count %d, falling back to 2 lanes\n", - dsi->lanes); + ret); dsi->lanes = 2; /* Old DT backward compatibility */ + } else { + dsi->lanes = ret; } ret = devm_mipi_dsi_attach(dev, dsi); -- 2.53.0