diff options
| author | Lars-Peter Clausen <lars@metafoo.de> | 2020-11-24 14:38:07 +0200 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2020-12-03 19:32:40 +0000 |
| commit | 0fb6ee8d0b5e90b72f870f76debc8bd31a742014 (patch) | |
| tree | 55394218e1ba4379c36b41e8a44dd54b4ec67a5f /include/linux/iio/adc | |
| parent | 6d74a3ee1ee1c7b62de656c26d370448ed5885c3 (diff) | |
iio: ad_sigma_delta: Don't put SPI transfer buffer on the stack
Use a heap allocated memory for the SPI transfer buffer. Using stack memory
can corrupt stack memory when using DMA on some systems.
This change moves the buffer from the stack of the trigger handler call to
the heap of the buffer of the state struct. The size increases takes into
account the alignment for the timestamp, which is 8 bytes.
The 'data' buffer is split into 'tx_buf' and 'rx_buf', to make a clearer
separation of which part of the buffer should be used for TX & RX.
Fixes: af3008485ea03 ("iio:adc: Add common code for ADI Sigma Delta devices")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201124123807.19717-1-alexandru.ardelean@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'include/linux/iio/adc')
| -rw-r--r-- | include/linux/iio/adc/ad_sigma_delta.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h index a3a838dcf8e4..7199280d89ca 100644 --- a/include/linux/iio/adc/ad_sigma_delta.h +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -79,8 +79,12 @@ struct ad_sigma_delta { /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. + * 'tx_buf' is up to 32 bits. + * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp, + * rounded to 16 bytes to take into account padding. */ - uint8_t data[4] ____cacheline_aligned; + uint8_t tx_buf[4] ____cacheline_aligned; + uint8_t rx_buf[16] __aligned(8); }; static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd, |