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[media] marvell-cam: Increase the DMA shutdown timeout
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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 <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Jonathan Corbet authored and Mauro Carvalho Chehab committed Mar 20, 2012
1 parent 0770d07 commit 482d35c
Showing 1 changed file with 9 additions and 1 deletion.
10 changes: 9 additions & 1 deletion drivers/media/video/marvell-ccic/mcam-core.c
Original file line number Diff line number Diff line change
Expand Up @@ -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? */
Expand Down Expand Up @@ -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;
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