From: Lars-Peter Clausen lars@metafoo.de
commit f954b098fbac4d183219ce5b42d76d6df2aed50a upstream.
When enabling the trigger and unmasking the end-of-sequence (EOS) interrupt the EOS interrupt should be cleared from the status register. Otherwise it is possible that it was still set from a previous capture. If that is the case the interrupt would fire immediately even though no conversion has been done yet and stale data is being read from the device.
The old code only clears the interrupt if the interrupt was previously unmasked. Which does not make much sense since the interrupt is always masked at this point and in addition masking the interrupt does not clear the interrupt from the status register. So the clearing needs to be done unconditionally.
Signed-off-by: Lars-Peter Clausen lars@metafoo.de Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver") Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iio/adc/xilinx-xadc-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/iio/adc/xilinx-xadc-core.c +++ b/drivers/iio/adc/xilinx-xadc-core.c @@ -660,7 +660,7 @@ static int xadc_trigger_set_state(struct
spin_lock_irqsave(&xadc->lock, flags); xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val); - xadc_write_reg(xadc, XADC_AXI_REG_IPISR, val & XADC_AXI_INT_EOS); + xadc_write_reg(xadc, XADC_AXI_REG_IPISR, XADC_AXI_INT_EOS); if (state) val |= XADC_AXI_INT_EOS; else