On 4/15/20 11:22 PM, Alexandre Belloni wrote:
There is no need to keep tx_buf around, it is only used for the conversion.
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
drivers/iio/adc/ti-ads8344.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c
index 6da50ea35217..9b2d3a8ea6bd 100644
--- a/drivers/iio/adc/ti-ads8344.c
+++ b/drivers/iio/adc/ti-ads8344.c
@@ -22,13 +22,7 @@
struct ads8344 {
struct spi_device *spi;
struct regulator *reg;
- /*
- * Lock protecting access to adc->tx_buff and rx_buff,
- * especially from concurrent read on sysfs file.
- */
- struct mutex lock;
-
- u8 tx_buf ____cacheline_aligned;
+ struct mutex lock; /* protect from concurrent conversions */
};
#define ADS8344_VOLTAGE_CHANNEL(chan, si) \
@@ -77,13 +71,13 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
int ret;
u8 buf[3];
spi_write() might use the buffer in a DMA transfer, so it can't be on
the stack and needs to be in its own cacheline.
- adc->tx_buf = ADS8344_START;
+ buf[0] = ADS8344_START;
if (!differential)
- adc->tx_buf |= ADS8344_SINGLE_END;
- adc->tx_buf |= ADS8344_CHANNEL(channel);
- adc->tx_buf |= ADS8344_CLOCK_INTERNAL;
+ buf[0] |= ADS8344_SINGLE_END;
+ buf[0] |= ADS8344_CHANNEL(channel);
+ buf[0] |= ADS8344_CLOCK_INTERNAL;
- ret = spi_write(spi, &adc->tx_buf, 1);
+ ret = spi_write(spi, buf, 1);
if (ret)
return ret;
