From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 42A1F20330; Tue, 26 Aug 2025 11:47:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756208877; cv=none; b=TcgEztVMylNTm9zJ7GOX9BC2YOeAW+cuMg3gUI0PAvE6bOOHHfJVn92hHhWsMHQeA50lRmc46ZBDyywD5U8sbrEddWqX4RBdA+NhFtKYr+9yLbOJ4i+Ok1A+So26x8nHE/1U+JMgn4ZdsTuJCS2j/4NIdmKRvpo4qXQBFM0/u0s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756208877; c=relaxed/simple; bh=3hxsMJAoBGfO+u0g5QJZ/AGMq/ywQBM2BDnZf42au1I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=amn2fFFKZfiHVuE5DTiTkw36lFqXceu29GOJsWDDLpTCuLzvyBv7vGE1wHbYGMrsNy2EDrZdidAfcQ07rx/eO7IBsFhBy8jRT6Npe0Upb/02HxxMbDldbYB2lEkO1fZ8zvAiUqvd1q+9a5A8JHNm6z0XPM3tOEhRc1DeubnKLu0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vBAOp8CK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vBAOp8CK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79706C4CEF1; Tue, 26 Aug 2025 11:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756208876; bh=3hxsMJAoBGfO+u0g5QJZ/AGMq/ywQBM2BDnZf42au1I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vBAOp8CKrci+CwkDWSF7e9k10X72osecA4Fx9SjQ5BK6RbQNBBicTCaG5ydRkJ1o/ IvsjBr4p4Aju+ehYOcn3qs6SW2lbwllLe3hGpplp+qdL8xwnauJvtLk1km4eGaec5q YcU7OoupsyM9puZaqjA8ZJRviQOU5pJOKiCLcmpo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , Stable@vger.kernel.org, Jonathan Cameron , Sasha Levin Subject: [PATCH 6.12 238/322] iio: temperature: maxim_thermocouple: use DMA-safe buffer for spi_read() Date: Tue, 26 Aug 2025 13:10:53 +0200 Message-ID: <20250826110921.783996259@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110915.169062587@linuxfoundation.org> References: <20250826110915.169062587@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Lechner [ Upstream commit ae5bc07ec9f73a41734270ef3f800c5c8a7e0ad3 ] Replace using stack-allocated buffers with a DMA-safe buffer for use with spi_read(). This allows the driver to be safely used with DMA-enabled SPI controllers. The buffer array is also converted to a struct with a union to make the usage of the memory in the buffer more clear and ensure proper alignment. Fixes: 1f25ca11d84a ("iio: temperature: add support for Maxim thermocouple chips") Signed-off-by: David Lechner Reviewed-by: Nuno Sá Link: https://patch.msgid.link/20250721-iio-use-more-iio_declare_buffer_with_ts-3-v2-1-0c68d41ccf6c@baylibre.com Cc: Signed-off-by: Jonathan Cameron [ iio_push_to_buffers_with_ts() => iio_push_to_buffers_with_timestamp() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/iio/temperature/maxim_thermocouple.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) --- a/drivers/iio/temperature/maxim_thermocouple.c +++ b/drivers/iio/temperature/maxim_thermocouple.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -122,8 +123,15 @@ struct maxim_thermocouple_data { struct spi_device *spi; const struct maxim_thermocouple_chip *chip; char tc_type; - - u8 buffer[16] __aligned(IIO_DMA_MINALIGN); + /* Buffer for reading up to 2 hardware channels. */ + struct { + union { + __be16 raw16; + __be32 raw32; + __be16 raw[2]; + }; + aligned_s64 timestamp; + } buffer __aligned(IIO_DMA_MINALIGN); }; static int maxim_thermocouple_read(struct maxim_thermocouple_data *data, @@ -131,18 +139,16 @@ static int maxim_thermocouple_read(struc { unsigned int storage_bytes = data->chip->read_size; unsigned int shift = chan->scan_type.shift + (chan->address * 8); - __be16 buf16; - __be32 buf32; int ret; switch (storage_bytes) { case 2: - ret = spi_read(data->spi, (void *)&buf16, storage_bytes); - *val = be16_to_cpu(buf16); + ret = spi_read(data->spi, &data->buffer.raw16, storage_bytes); + *val = be16_to_cpu(data->buffer.raw16); break; case 4: - ret = spi_read(data->spi, (void *)&buf32, storage_bytes); - *val = be32_to_cpu(buf32); + ret = spi_read(data->spi, &data->buffer.raw32, storage_bytes); + *val = be32_to_cpu(data->buffer.raw32); break; default: ret = -EINVAL; @@ -167,9 +173,9 @@ static irqreturn_t maxim_thermocouple_tr struct maxim_thermocouple_data *data = iio_priv(indio_dev); int ret; - ret = spi_read(data->spi, data->buffer, data->chip->read_size); + ret = spi_read(data->spi, data->buffer.raw, data->chip->read_size); if (!ret) { - iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, iio_get_time_ns(indio_dev)); }