From cf15a2b518b3e6991ef1c2f87e9a7f7e4afa7b77 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Wed, 3 Aug 2022 13:28:41 +0300 Subject: [PATCH] iio: adc: at91-sama5d2_adc: exit from write_raw() when buffers are enabled When buffers are enabled conversion may start asynchronously thus allowing changes on actual hardware could lead to bad behavior. Thus do not allow changing oversampling ratio and sample frequency when if iio_device_claim_direct_mode() returns with error. Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20220803102855.2191070-6-claudiu.beznea@microchip.com Signed-off-by: Jonathan Cameron --- drivers/iio/adc/at91-sama5d2_adc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index e2c82c5a2fac0..64943d8ea8692 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -1641,6 +1641,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, int val, int val2, long mask) { struct at91_adc_state *st = iio_priv(indio_dev); + int ret; switch (mask) { case IIO_CHAN_INFO_OVERSAMPLING_RATIO: @@ -1650,20 +1651,29 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, /* if no change, optimize out */ if (val == st->oversampling_ratio) return 0; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; mutex_lock(&st->lock); st->oversampling_ratio = val; /* update ratio */ at91_adc_config_emr(st); mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return 0; case IIO_CHAN_INFO_SAMP_FREQ: if (val < st->soc_info.min_sample_rate || val > st->soc_info.max_sample_rate) return -EINVAL; + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; mutex_lock(&st->lock); at91_adc_setup_samp_freq(indio_dev, val); mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return 0; default: return -EINVAL; -- 2.30.2