From nobody Sun Dec 28 22:54:20 2025 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 ADDE5C10F04 for ; Mon, 4 Dec 2023 12:29:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343978AbjLDM3H (ORCPT ); Mon, 4 Dec 2023 07:29:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233019AbjLDM3F (ORCPT ); Mon, 4 Dec 2023 07:29:05 -0500 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08487D2 for ; Mon, 4 Dec 2023 04:29:11 -0800 (PST) Received: by mail-wm1-x330.google.com with SMTP id 5b1f17b1804b1-40c0e37cfafso3760105e9.0 for ; Mon, 04 Dec 2023 04:29:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1701692949; x=1702297749; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=MkkECO5iEe8wffVmp+N+jpk0G+DJrLKzEev9h10F0Rg=; b=HZGeiMgySiUnWJmhgw+zXewpTQZsiLfX69MWrxIehWuO5AFYy+Vzi0fzJI2iS0Z74X w2OeWSyXyslK6/G2dBtuSiUYNmJK33wQo3+o6xBKYzMiWvFpe5a7ZrrhCB2zMdp2LLag M3HJZiGboTgpfqTUxKWMSbqLZwdiq8AIMM5oyb1qHT2pGcA0UUTNZzETY1cgV8w0HcJN vvSyiKvUQJmn2OxOZN5avuc9YrzViCcAS6Mt3oC6EmDC66Xcw5Gz/gvKmfiPs2b/qVVr RlZ2RcVzWBSx/UYZjosP+j/PC9mFjwZwzPsTl8EuBj8JLFR7877jic5Egv1+Yb6bmcQ5 +Znw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701692949; x=1702297749; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=MkkECO5iEe8wffVmp+N+jpk0G+DJrLKzEev9h10F0Rg=; b=UmbrLUTewA6PVa7g3N7x3rQh421TGw+D0wWOGSf0vz7VhKo+bXy0UsA1/v/+qdN3UO DkyEzJE0QtARhyPbGGE841J5IR3GEiJ0KWvNrwG5mXwoBdO3oCpQ0McBPgnxdoV5cQTn vQp/A2dmJle8XPf0eRL4SzKzIhTTvWgG1cUBY+aJcC0BpjUZ1Zvsh+KmPVTdZXPIVey5 PbYDHGbLVocIKsR+VDeem0nwwQxyO+G4tKddvZf+J/KiB8CCqDjVBXou4vw6ehZME4Ql Aku3ChKq+vEdBcy/MWEPAR9itrFwG7U1P7z87I8/ubRSgau73Y3F3h14uRA4G95S5LQ7 0wzA== X-Gm-Message-State: AOJu0Yx6ICySx1nQ1z6beELUAGzJEMpdeUDvnnwvI1AeHEqLHIWElbd9 d8KXMdjraATHJoTrBQkr68T2+g== X-Google-Smtp-Source: AGHT+IEhBK8pDeFMWjsr+8bKrzXeC11m8+GcPR+3mHNKpiYY/iuhyUeTu2UUAAGueQ/HmM7P67v+lw== X-Received: by 2002:a7b:c041:0:b0:40b:42d4:3319 with SMTP id u1-20020a7bc041000000b0040b42d43319mr2561709wmc.0.1701692949452; Mon, 04 Dec 2023 04:29:09 -0800 (PST) Received: from localhost ([102.36.222.112]) by smtp.gmail.com with ESMTPSA id j11-20020a05600c190b00b0040b47c69d08sm18464512wmq.18.2023.12.04.04.29.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Dec 2023 04:29:09 -0800 (PST) Date: Mon, 4 Dec 2023 15:29:00 +0300 From: Dan Carpenter To: Sean Paul Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Inki Dae , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] drm/bridge: nxp-ptn3460: fix i2c_master_send() error checking Message-ID: <0cdc2dce-ca89-451a-9774-1482ab2f4762@moroto.mountain> MIME-Version: 1.0 Content-Disposition: inline X-Mailer: git-send-email haha only kidding Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The i2c_master_send/recv() functions return negative error codes or the number of bytes that were able to be sent/received. This code has two problems. 1) Instead of checking if all the bytes were sent or received, it checks that at least one byte was sent or received. 2) If there was a partial send/receive then we should return a negative error code but this code returns success. Fixes: a9fe713d7d45 ("drm/bridge: Add PTN3460 bridge driver") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter --- This is from static analysis and code review. It's always a concern when you add stricter error handling that something will break. drivers/gpu/drm/bridge/nxp-ptn3460.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/bridge/nxp-ptn3460.c b/drivers/gpu/drm/bridge/= nxp-ptn3460.c index d81920227a8a..9b7eb8c669c1 100644 --- a/drivers/gpu/drm/bridge/nxp-ptn3460.c +++ b/drivers/gpu/drm/bridge/nxp-ptn3460.c @@ -56,13 +56,13 @@ static int ptn3460_read_bytes(struct ptn3460_bridge *pt= n_bridge, char addr, ret =3D i2c_master_send(ptn_bridge->client, &addr, 1); if (ret <=3D 0) { DRM_ERROR("Failed to send i2c command, ret=3D%d\n", ret); - return ret; + return ret ?: -EIO; } =20 ret =3D i2c_master_recv(ptn_bridge->client, buf, len); - if (ret <=3D 0) { + if (ret !=3D len) { DRM_ERROR("Failed to recv i2c data, ret=3D%d\n", ret); - return ret; + return ret < 0 ? ret : -EIO; } =20 return 0; @@ -78,9 +78,9 @@ static int ptn3460_write_byte(struct ptn3460_bridge *ptn_= bridge, char addr, buf[1] =3D val; =20 ret =3D i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); - if (ret <=3D 0) { + if (ret !=3D ARRAY_SIZE(buf)) { DRM_ERROR("Failed to send i2c command, ret=3D%d\n", ret); - return ret; + return ret < 0 ? ret : -EIO; } =20 return 0; --=20 2.42.0