From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D3209242D6A for ; Mon, 27 Apr 2026 21:33:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777325610; cv=none; b=L8Pjmxyc8ohjC4AVcPlkcKnuc+A92DQHASiPKocRRVvpsqGldg3rz1lpR+qzgpH7OEYrRVtOYyO971Mz4bDDlml5gEna/QQKgM2sQhsTLcfNQy4JTy9EezyCwbdquresY/+OWFmUkMuhBlQTPno+fP5yzJxvwTqwYctN0hX3oyc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777325610; c=relaxed/simple; bh=bmBhda2SXfNu+pnH6eDyxuTr7J9+ijLQlaJR1l0HlYE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=owoa3lbYB4EikLDKLKFlVXsUsYPHEWOWTfVIuJvI9pB72WYLYgC30E5OrRPAnK18Y14s84BESHr/YrzMiarcXYXqni36QpwF7lS0qUKj5Hd9cqi13hxTBGy+MsujuIfP/LzhBEQ7tw4JAYLTDd2+ZlhpcwD17Gu/gtmMjEcWIeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=YICtelMo; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YICtelMo" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-4838c15e3cbso99606665e9.3 for ; Mon, 27 Apr 2026 14:33:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1777325606; x=1777930406; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=6Tqviw2J4SQxec8cpPz4dVaAo9bKFvw3GTwF8/MdD9U=; b=YICtelMoUCoiIAqvNn19Q+mI5Ro/5np4ITUGNkefe5c7HAiGVHHWNIS6TQjv8Bisly PJqd9NWK0xl86SIFNH7/6qTuGh+IorQpxPNOVhjAwcZGQc4g1uW19AGkPBxryqs6MN60 A+NyATtn0bCiGkyZitbsEI1JrrhdkwQ0WLVdtzdo7QRawLpsTeYS8deL9PI2iHItEOLS a3+TOSdR3eNCgNQ9wrMsti2Dljovetr1HcJ6CyXZOCxV74qjBE5rmt6PdUb0kU0eJ5A+ mlwQSs3kCaxq3WzGpbcjtHMgOohXBIRDvRs++9oFtPvdM4RZBZJmxYWGstBO+szRi1/d o9WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777325606; x=1777930406; 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=6Tqviw2J4SQxec8cpPz4dVaAo9bKFvw3GTwF8/MdD9U=; b=b1iZ/zkjbXMrvu2cp4bZx/MTv5HuVsC6SzbeoRS1WNq5/OupdCt+WYKkd+PRIVvoTc +PmYNRkz6vmzLtA+BjyB5WCSoY8ZtUYF1v3Y+kXD0iNuapwdFBFiyXMpUBSOd6bIfAZ5 BqXevECNNxxH6evDXhemYYxcuHfhKJfqN+k3B6jIGR6odZ17BwrBC2Lg1N2HbP8V84W3 fbmOkeuB4BRJYh1UNnHRKDBumrW1uk9aeVldO3PKFirbHwDlgHQaH5qtYrGokTo9WF2c qdDn0591KumE1oiMpqLK8FE2Z1caELY2iL8zrYmVq51/QYPexAjsZa/gJx2xZvOU07L+ 3/lQ== X-Forwarded-Encrypted: i=1; AFNElJ+du31v2YnzW5OexCAmPZjewPep3Uvc7Kc4T1S+JQvb9D3/XWMcFmbBiLtWuGXK1pfEzc8TDBhyOE//Tdg=@vger.kernel.org X-Gm-Message-State: AOJu0YwGkn5IT4vOKnLBFRgC6llI5CMn8WGqKZXP1OO4mb+p/63eAXkt 0Atv5+3e7XII70Aen3gWH2FbtQmmW6xiA+dxmzl8OeX0oTrkXFleH4e2gi/HfJ7e X-Gm-Gg: AeBDietUVbASijyvR7zaJ70qjzqDNXXCJ7Vt9hcHWyMxtCNZlt8AKZriFd5dY3DiD4d IQp8ZKMR2KElq7Ty4LZO5ITinbHzFsj8/bnm9Yp+1w8xpkFWpgdkrZ5CU9ApIio3P8izA16NMX8 4pjKS3YHMHFYbkn30GyPYQa5RYooYZCJPTF9EC7g+eFV7/Fh97fKsuvYlUrgVlj+MRgwqgPf5hZ tL7aCfwHW5G7DJvbnAn29yfbzT7sNoPf487UgFk/nfbVY84j6nKPkz3l4nljA2mGG1thAglC614 K+mUX/Vf3clR+/XX008W3/vCZiMj3q4kuPAE6tV5WlyD4COnziDGJVRkjixqwEA05MohRLsCmvA fBNwWgpAQZAFAUXqiStzGyP53blJdgjooufsq37ho25URcaxJ8oUqv2eCA7KP3eWBYM53a0h/R6 MKYr0GZz+1krBSjiYG9Xge+/KFFw41IhbXswVh1fRgIh+NgJxYlilrbiJMLZA= X-Received: by 2002:a05:600c:1f0d:b0:485:4bd1:4c64 with SMTP id 5b1f17b1804b1-48a77b27776mr5133205e9.31.1777325606128; Mon, 27 Apr 2026 14:33:26 -0700 (PDT) Received: from localhost.localdomain ([196.235.239.18]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-48a773af544sm13359555e9.6.2026.04.27.14.33.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Apr 2026 14:33:25 -0700 (PDT) From: Salah Triki To: Jonathan Cameron , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , Andy Shevchenko Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Salah Triki Subject: [PATCH v3] iio: dac: max5821: fix return value check in powerdown sync Date: Mon, 27 Apr 2026 22:33:19 +0100 Message-ID: <20260427213319.25767-1-salah.triki@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The function max5821_sync_powerdown_mode() returned the result of i2c_master_send() directly. If a partial transfer occurred, it would be incorrectly treated as a success by the caller. While the caller currently handles the positive return value of 2 as success, this patch refactors the function to return 0 on full success and -EIO on short writes. This ensures robust error handling for incomplete transfers and improves code maintainability by using sizeof(outbuf). Fixes: 472988972737 ("iio: add support of the max5821") Signed-off-by: Salah Triki --- Changes in v3: - Remove blank lines Changes in v2: - Replace magic number '2' with 'sizeof(outbuf)' for better maintainability. - Remove redundant blank line between i2c_master_send() and error check. - Update commit message to clarify that the 'Fixes' tag is primarily for handling partial transfers (short writes), as the caller already handled the success case correctly. drivers/iio/dac/max5821.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iio/dac/max5821.c b/drivers/iio/dac/max5821.c index e7e29359f8fe..dd4e35460195 100644 --- a/drivers/iio/dac/max5821.c +++ b/drivers/iio/dac/max5821.c @@ -90,6 +90,7 @@ static int max5821_sync_powerdown_mode(struct max5821_data *data, const struct iio_chan_spec *chan) { u8 outbuf[2]; + int ret; outbuf[0] = MAX5821_EXTENDED_COMMAND_MODE; @@ -103,7 +104,13 @@ static int max5821_sync_powerdown_mode(struct max5821_data *data, else outbuf[1] |= MAX5821_EXTENDED_POWER_UP; - return i2c_master_send(data->client, outbuf, 2); + ret = i2c_master_send(data->client, outbuf, sizeof(outbuf)); + if (ret < 0) + return ret; + if (ret != sizeof(outbuf)) + return -EIO; + + return 0; } static ssize_t max5821_write_dac_powerdown(struct iio_dev *indio_dev, -- 2.43.0