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authorRadu Sabau <radu.sabau@analog.com>2026-05-27 12:38:38 +0300
committerJonathan Cameron <jic23@kernel.org>2026-05-29 09:57:06 +0100
commitc72da0688575e5ef39c36bb44fed53aa18f8ae65 (patch)
treeff71dea48b1f9105913cfb0347ed3602eb9d273e
parentc123ca6ee26ad98f70a866ff428b08145c5a24fe (diff)
downloadlinux-next-history-c72da0688575e5ef39c36bb44fed53aa18f8ae65.tar.gz
iio: adc: ad_sigma_delta: fix CS held asserted and state leaks
In ad_sigma_delta_single_conversion(), set_mode(AD_SD_MODE_IDLE) and disable_one() were called from the out: block while keep_cs_asserted was still true. This caused any SPI transfer issued by those callbacks to carry cs_change=1, leaving CS permanently asserted after the conversion. Fix by moving both calls into the out_unlock: block, after keep_cs_asserted is cleared, matching the pattern already used in ad_sd_calibrate(). In the error path of ad_sd_buffer_postenable(), if an operation fails after set_mode(AD_SD_MODE_CONTINUOUS) has already succeeded (e.g. spi_offload_trigger_enable()), the device is left in continuous conversion mode with CS physically asserted. Additionally, bus_locked remaining true after spi_bus_unlock() causes subsequent SPI operations to call spi_sync_locked() without the bus lock actually held, allowing concurrent SPI access. Fix the error path by clearing keep_cs_asserted first, then calling set_mode(AD_SD_MODE_IDLE) to revert the device mode and deassert CS, then clearing bus_locked before releasing the bus. For devices that implement neither set_mode nor disable_one (such as MAX11205, which has no physical CS pin), no SPI transfer is issued during cleanup and the cs_change flag has no effect on any physical line. Fixes: 132d44dc6966 ("iio: adc: ad_sigma_delta: Check for previous ready signals") Signed-off-by: Radu Sabau <radu.sabau@analog.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r--drivers/iio/adc/ad_sigma_delta.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
index a955556f9ec88..651ade67ad2e9 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -441,11 +441,10 @@ int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
out:
ad_sd_disable_irq(sigma_delta);
- ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
- ad_sigma_delta_disable_one(sigma_delta, chan->address);
-
out_unlock:
sigma_delta->keep_cs_asserted = false;
+ ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
+ ad_sigma_delta_disable_one(sigma_delta, chan->address);
sigma_delta->bus_locked = false;
spi_bus_unlock(sigma_delta->spi->controller);
out_release:
@@ -578,6 +577,9 @@ static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
return 0;
err_unlock:
+ sigma_delta->keep_cs_asserted = false;
+ ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
+ sigma_delta->bus_locked = false;
spi_bus_unlock(sigma_delta->spi->controller);
spi_unoptimize_message(&sigma_delta->sample_msg);