[RESEND][PATCH] [media] atmel-isc: start dma in some scenario

From: Songjun Wu
Date: Tue Oct 18 2016 - 02:15:54 EST


If a new vb buf is added to vb queue, the queue is
empty and steaming, dma should be started.

Signed-off-by: Songjun Wu <songjun.wu@xxxxxxxxxxxxx>
---

drivers/media/platform/atmel/atmel-isc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c
index ccfe13b..ff403d5 100644
--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -617,7 +617,14 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
unsigned long flags;

spin_lock_irqsave(&isc->dma_queue_lock, flags);
- list_add_tail(&buf->list, &isc->dma_queue);
+ if (!isc->cur_frm && list_empty(&isc->dma_queue) &&
+ vb2_is_streaming(vb->vb2_queue)) {
+ isc->cur_frm = buf;
+ isc_start_dma(isc->regmap, isc->cur_frm,
+ isc->current_fmt->reg_dctrl_dview);
+ } else {
+ list_add_tail(&buf->list, &isc->dma_queue);
+ }
spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
}

--
2.7.4