From 482d35c41f2efb0408624e222bbc9efc0b3518eb Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Fri, 16 Mar 2012 19:14:52 -0300 Subject: [PATCH] [media] marvell-cam: Increase the DMA shutdown timeout 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 Signed-off-by: Mauro Carvalho Chehab --- 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 b26118246763..050724f8d3e6 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; -- 2.45.2