[PATCH 04/10] media: microchip-isc: disable histogram and flush AWB work on stop

[Balakrishnan Sambath]

isc_stop_streaming() masked the DMA done interrupt but left the
histogram enabled, so a HISDONE that fired just before the stop could
still queue isc_awb_work() after pm_runtime_put_sync() gated the clocks.
isc_awb_work() reads the histogram registers in isc_hist_count() before
taking its own PM reference, so the access faults on the suspended
device.

Disable the histogram and flush the work before dropping the PM
reference, mirroring the start_streaming error path.

Fixes: 91b4e487b0c6 ("media: microchip: add ISC driver as Microchip ISC")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Balakrishnan Sambath <balakrishnan.s@xxxxxxxxxxxxx>
---
 drivers/media/platform/microchip/microchip-isc-base.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/platform/microchip/microchip-isc-base.c b/drivers/media/platform/microchip/microchip-isc-base.c
index 3245dd7cb980..8f255a4c4e7a 100644
--- a/drivers/media/platform/microchip/microchip-isc-base.c
+++ b/drivers/media/platform/microchip/microchip-isc-base.c
@@ -425,9 +425,13 @@ static void isc_stop_streaming(struct vb2_queue *vq)
 	/* Disable DMA interrupt */
 	regmap_write(isc->regmap, ISC_INTDIS, ISC_INT_DDONE);
 
+	isc_set_histogram(isc, false);
+
 	/* let a running IRQ handler finish before the clock is disabled */
 	synchronize_irq(isc->irq);
 
+	cancel_work_sync(&isc->awb_work);
+
 	pm_runtime_put_sync(isc->dev);
 
 	/* Disable stream on the sub device */

-- 
2.34.1