From 348eb0b2c4f0f912d626fa789dfeb084b083e1f0 Mon Sep 17 00:00:00 2001 From: Andrea Merello Date: Thu, 12 Sep 2019 16:43:08 +0200 Subject: [PATCH] iio: ad7949: fix incorrect SPI xfer len This driver supports 14-bits and 16-bits devices. All of them have a 14-bit configuration registers. All SPI trasfers, for reading AD conversion results and for writing the configuration register, fit in two bytes. The driver always uses 4-bytes xfers which seems at least pointless (maybe even harmful). This patch trims the SPI xfer len and the buffer size to two bytes. Signed-off-by: Andrea Merello Reviewed-by: Alexandru Ardelean Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ad7949.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c index 518044c31a73..5c2b3446fa4a 100644 --- a/drivers/iio/adc/ad7949.c +++ b/drivers/iio/adc/ad7949.c @@ -54,7 +54,7 @@ struct ad7949_adc_chip { u8 resolution; u16 cfg; unsigned int current_channel; - u32 buffer ____cacheline_aligned; + u16 buffer ____cacheline_aligned; }; static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val, @@ -67,7 +67,7 @@ static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val, struct spi_transfer tx[] = { { .tx_buf = &ad7949_adc->buffer, - .len = 4, + .len = 2, .bits_per_word = bits_per_word, }, }; @@ -95,7 +95,7 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, struct spi_transfer tx[] = { { .rx_buf = &ad7949_adc->buffer, - .len = 4, + .len = 2, .bits_per_word = bits_per_word, }, };