From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f47.google.com (mail-wm1-f47.google.com [209.85.128.47]) (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 81D0538236E for ; Sun, 6 Sep 2026 11:43:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788694997; cv=none; b=eV8DVAmS5zvm51ZwjMPWlJZw0efntAQe7c/v3LxCeLLDAiHROSMCmVcdZhqz43YsYdIMGnC63IdhMxhGUvb931LBBcxtTod6Ax3YgrqvBi7cNkErcAdZ25lLn9fnFOcXNs1CHYQobcw0LcOMslFwADenhnSiu27LvFxjJqPL1EY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788694997; c=relaxed/simple; bh=Tgs81imXHXxl5PUz46cTacwZvL65MXU8w2OLv0AdJH4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SQls/mzXZMXU4cKOTQxeKTVW6LF0SXZBtcM4jMbxn6/AxSccsRKo5GoP0gs6LkNLeRBJvwoqTMgqU98lHnLQiBUQqhcASkqiOAzCFp1Y9+dj8iKbM6jeTSF+bfZ4FhIuVxtfBwFPzjZtiYWeyQvaZ+JQsQZvcXo+Ie/s6Sa2Nmk= 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=W5oJ9LOG; arc=none smtp.client-ip=209.85.128.47 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="W5oJ9LOG" Received: by mail-wm1-f47.google.com with SMTP id 5b1f17b1804b1-49557167508so30753815e9.1 for ; Sun, 06 Sep 2026 04:43:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788694994; x=1789299794; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=0kt+nixPnxV+vJED7IjIV2XXQGlXwwe0QJtiMVPgU48=; b=W5oJ9LOGDiQeEod7fUdyToNv9hRSbM1NlUGq2bWQZtOwZ2LENjSnybCJjQ6tZ1znhM eqNlNNP9n1uN32okJ+NvB2N74f5/Xn0cmCQgB6mMPTdPu93aM057xILVd9GFPb9X56sj wEP+FLPPQ3wWNcQYde8265lFEi4yYVDiNoFlrt4DZeqtcYHIQxuRy55zm1i4U3hCjKss RZdMNNvT66NXmo5gEouTqi2KYJOKS/IfQVUky3IWeBfv2EQtQ2vdZtMgOkF9pZBk/2Rj O6h9FY01J3TQlOfZovq+ixqJbhIr/0P+xryEzLs7AEnt6Rf713jJd5oWv/iP91vJwzAh iBtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788694994; x=1789299794; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=0kt+nixPnxV+vJED7IjIV2XXQGlXwwe0QJtiMVPgU48=; b=NfVIkVGF13G9Ubr998TDHnx3dwvpWl9cTn43NEiKSpH8+8qyGZ4lw/mTHkh4+sNgRs nxEU75XynbZGYlG6xbCnsGXqHHIWhxWB7Gmenwp8iN7XccCTYBE9I+5ToNDUZgQn4Zt5 lelCfB4OWiQlev//QH9uY5mjFjP5segngUxtpmvoOeM3+TwqT4gM7uBbUP64ZWf5TkLw PZqyqPzRpkAZXmaVLCF9ib4wxHh5ycpkW3gqHvyrshbNRCg+JMG89g/AB3h1p243ZZWa VYrJLB+o25xLiMr7cZckQYjzhOu3zkWBG9x5AzOs2cMSMFd77wLkmLNa4SYbXvzBfIvy 3K5w== X-Forwarded-Encrypted: i=1; AKwUvByyS3UAybMrSUXrpg8/r04AtiT16pZ3waWPjtCFS9hSeR94F+QNcxJSfjrG1ceuVmV5FB7bdy8gBfzRU8c=@vger.kernel.org X-Gm-Message-State: AFuF++ntxUc/ZvP5vFp3mWBdbDUpaaVO8R8uC2SE4Ip34mbONwdfRTyE wo+KydBGzOpFohcDz01FdEyPSRIjnnJXtX4pofr0JiG3FtH37giav6p6 X-Gm-Gg: AYBFou3HcU0qCS7FxdX2w1L36YRDCp3dK00UbGOl7hCm/indcsAfp5uiZDDXeQJjROy otNEIeUK2EvgBET8F1Db1YTJ3YlgXsRDl66fM2fe9pi8hiHuiMThSFvgqhgiyjLvwIfY4u0l12I T+R3ymPFONd4z/0dfHpiCVLKNP38tTXWMbBdv9sgUH952/YbxkSGrGdPn4QMxqn7r4YORNQIAo5 VJ7YC1Srp9ZyXzxl357QQTgqq4ubypPFKNkdkutjxjSiF+8h28jpwII/aT6Yy2mQeiZ5zWsmh1F lxdeDqemgX9qoeW6b0xL5v3YcmtsEEGJAgqzrBe01LVQNpZwpEsrzQ8SaszbPjavgEbfLTmjv04 M1YRfDgfaKkSHFzhIkMMwH0PH9k8Ombyq+j82efLToDvKGVKOsKMmis1CV3BQzrO+a+URH3yEgJ FwFKaV6hv2CgB7eYGE+HoPD4/vOpzvq0nBBGasAPOV8kSNP9R+nqoiUruNOLBrNaSlAnvEjyGsV GvPqM0T8exK0h+am3U= X-Received: by 2002:a05:600c:6383:b0:49c:e88b:b7ce with SMTP id 5b1f17b1804b1-49cf823f147mr327098175e9.11.1788694993614; Sun, 06 Sep 2026 04:43:13 -0700 (PDT) Received: from fedora ([154.182.82.204]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4858ab73c2bsm19356223f8f.22.2026.09.06.04.43.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 06 Sep 2026 04:43:13 -0700 (PDT) From: Abdelnasser Hussein To: gregkh@linuxfoundation.org, jic23@kernel.org, nuno.sa@analog.com, Michael.Hennerich@analog.com Cc: dlechner@baylibre.com, andy@kernel.org, linux@analog.com, linux-iio@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Abdelnasser Hussein Subject: [PATCH v4 2/2] staging: iio: adc: ad7816: Use DMA-safe buffer for SPI read Date: Sun, 6 Sep 2026 14:40:49 +0300 Message-ID: <20260906114049.32912-3-abdelnasserhussein11@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260906114049.32912-1-abdelnasserhussein11@gmail.com> References: <20260906114049.32912-1-abdelnasserhussein11@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Stack buffers are not guaranteed to be cache-coherent and must not be used with SPI reads, which can trigger issues with VMAP_STACK. Fix this by using a dedicated DMA-safe rx_buf aligned with IIO_DMA_MINALIGN. Also, correct the sizeof() argument from *data to chip->rx_buf to match the buffer size. Fixes: 7024425db64a ("staging: iio: adc: new driver for AD7816 devices") Signed-off-by: Abdelnasser Hussein --- drivers/staging/iio/adc/ad7816.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c index ab80b3a889bb..e14ae805f076 100644 --- a/drivers/staging/iio/adc/ad7816.c +++ b/drivers/staging/iio/adc/ad7816.c @@ -52,6 +52,8 @@ struct ad7816_chip_info { u8 oti_data[AD7816_CS_MAX + 1]; u8 channel_id; /* 0 always be temperature */ u8 mode; + struct mutex lock; /* protect device state during SPI transfers */ + __be16 rx_buf __aligned(IIO_DMA_MINALIGN); }; enum ad7816_type { @@ -94,13 +96,13 @@ static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data) gpiod_set_value(chip->rdwr_pin, 0); gpiod_set_value(chip->rdwr_pin, 1); - ret = spi_read(spi_dev, &buf, sizeof(*data)); + ret = spi_read(spi_dev, &chip->rx_buf, sizeof(chip->rx_buf)); if (ret < 0) { dev_err(&spi_dev->dev, "SPI data read error\n"); return ret; } - *data = be16_to_cpu(buf); + *data = be16_to_cpu(chip->rx_buf); return ret; } -- 2.54.0