From: Alexandru Tachici <alexandru.tachici@analog.com> stable inclusion from stable-5.10.75 commit d078043a1775e6564ae70bf849ce183713d13d5b bugzilla: 182987 https://gitee.com/openeuler/kernel/issues/I4I3MP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit e081102f3077aa716974ccebec97003c890d5641 upstream. Correct IRQ flag here is falling. In Sigma-Delta devices the SDO line is also used as an interrupt. Leaving IRQ on level instead of falling might trigger a sample read when the IRQ is enabled, as the SDO line is already low. Not sure if SDO line will always immediately go high in ad_sd_buffer_postenable before the IRQ is enabled. Also the datasheet seem to explicitly say the falling edge of the SDO should be used as an interrupt:
From the AD7780 datasheet: " The DOUT/Figure 22 RDY falling edge can be used as an interrupt to a processor"
Fixes: da4d3d6bb9f6 ("iio: adc: ad-sigma-delta: Allow custom IRQ flags") Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com> Cc: <Stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210906065630.16325-3-alexandru.tachici@analog.co... Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- drivers/iio/adc/ad7780.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/adc/ad7780.c b/drivers/iio/adc/ad7780.c index 42e7e8e595d1..c70048bc791b 100644 --- a/drivers/iio/adc/ad7780.c +++ b/drivers/iio/adc/ad7780.c @@ -203,7 +203,7 @@ static const struct ad_sigma_delta_info ad7780_sigma_delta_info = { .set_mode = ad7780_set_mode, .postprocess_sample = ad7780_postprocess_sample, .has_registers = false, - .irq_flags = IRQF_TRIGGER_LOW, + .irq_flags = IRQF_TRIGGER_FALLING, }; #define _AD7780_CHANNEL(_bits, _wordsize, _mask_all) \ -- 2.20.1