From: Alexandru Tachici alexandru.tachici@analog.com
stable inclusion from stable-5.10.75 commit 4425d059aa2e907c04771bb6550f31973c843262 bugzilla: 182987 https://gitee.com/openeuler/kernel/issues/I4I3MP
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 1a913270e57a8e7f1e3789802f1f64e6d0654626 upstream.
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 AD7793 datasheet: " The DOUT/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/20210906065630.16325-4-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/ad7793.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c index 440ef4c7be07..7c9c95c252cf 100644 --- a/drivers/iio/adc/ad7793.c +++ b/drivers/iio/adc/ad7793.c @@ -206,7 +206,7 @@ static const struct ad_sigma_delta_info ad7793_sigma_delta_info = { .has_registers = true, .addr_shift = 3, .read_mask = BIT(6), - .irq_flags = IRQF_TRIGGER_LOW, + .irq_flags = IRQF_TRIGGER_FALLING, };
static const struct ad_sd_calib_data ad7793_calib_arr[6] = {