From: Songjun Wu <songjun.wu@microchip.com>
Date: Wed, 28 Sep 2016 05:28:57 +0000 (-0300)
Subject: [media] atmel-isc: start dma in some scenario
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=fa8bbe0a8567bf4eb87e82739465360a6797c91b;p=linux-beck.git

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

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@microchip.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---

diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c
index ccfe13b7d3f8..8e25d3f56438 100644
--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -617,7 +617,13 @@ 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);
 }