Experience shows that, on the Armada platform, it can take as much as 120ms
for the DMA engine to actually shut down after it has been told to. So a
40ms timeout is not adequate; use 150ms instead. Also make sure we don't
leave the DMA_ACTIVE flag set once things are down.
Signed-off-by: Jonathan Corbet <cor...@lwn.net>
---
drivers/media/video/marvell-ccic/mcam-core.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/media/video/marvell-ccic/mcam-core.c
b/drivers/media/video/marvell-ccic/mcam-core.c
index b261182..050724f 100644
--- a/drivers/media/video/marvell-ccic/mcam-core.c
+++ b/drivers/media/video/marvell-ccic/mcam-core.c
@@ -742,7 +742,14 @@ static void mcam_ctlr_stop_dma(struct mcam_camera *cam)
mcam_ctlr_stop(cam);
cam->state = S_IDLE;
spin_unlock_irqrestore(&cam->dev_lock, flags);
- msleep(40);
+ /*
+ * This is a brutally long sleep, but experience shows that
+ * it can take the controller a while to get the message that
+ * it needs to stop grabbing frames. In particular, we can
+ * sometimes (on mmp) get a frame at the end WITHOUT the
+ * start-of-frame indication.
+ */
+ msleep(150);
if (test_bit(CF_DMA_ACTIVE, &cam->flags))
cam_err(cam, "Timeout waiting for DMA to end\n");
/* This would be bad news - what now? */
@@ -885,6 +892,7 @@ static int mcam_read_setup(struct mcam_camera *cam)
* Turn it loose.
*/
spin_lock_irqsave(&cam->dev_lock, flags);
+ clear_bit(CF_DMA_ACTIVE, &cam->flags);
mcam_reset_buffers(cam);
mcam_ctlr_irq_enable(cam);
cam->state = S_STREAMING;
--
1.7.9.3
--
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