From: Radu Sabau Date: Wed, 27 May 2026 09:38:38 +0000 (+0300) Subject: iio: adc: ad_sigma_delta: fix CS held asserted and state leaks X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=c72da0688575e5ef39c36bb44fed53aa18f8ae65;p=thirdparty%2Fkernel%2Flinux.git 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 Cc: Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index a955556f9ec8..651ade67ad2e 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);