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[RFC,3/4,media] ti-vpe: Do not perform job transaction atomically

Message ID 1412951223-4711-4-git-send-email-nikhil.nd@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Nikhil Devshatwar Oct. 10, 2014, 2:27 p.m. UTC
Current VPE driver does not start the job untill all the buffers for
a transaction are not queued. When running in multiple context, this might
increase the processing latency.

Alternate solution would be to try to continue the same context as long as
buffers for the transaction are ready; else switch the conext. This may
increase number of context switches but it reduces latency significantly.

In this approach, the job_ready always succeeds as long as there are buffers
on the CAPTURE and OUTPUT stream. Processing may start immediately as the
first 2 iterations don't need extra source buffers. Shift all the source buffers
after each iteration and remove the oldest buffer.

Also, with this removes the constraint of pre buffering 3 buffers before call
to STREAMON in case of deinterlacing.

Signed-off-by: Nikhil Devshatwar <nikhil.nd@ti.com>
---
 drivers/media/platform/ti-vpe/vpe.c |   32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)
diff mbox

Patch

diff --git a/drivers/media/platform/ti-vpe/vpe.c b/drivers/media/platform/ti-vpe/vpe.c
index a11044f..e37102b 100644
--- a/drivers/media/platform/ti-vpe/vpe.c
+++ b/drivers/media/platform/ti-vpe/vpe.c
@@ -907,15 +907,14 @@  static struct vpe_ctx *file2ctx(struct file *file)
 static int job_ready(void *priv)
 {
 	struct vpe_ctx *ctx = priv;
-	int needed = ctx->bufs_per_job;
 
-	if (ctx->deinterlacing && ctx->src_vbs[2] == NULL)
-		needed += 2;	/* need additional two most recent fields */
-
-	if (v4l2_m2m_num_src_bufs_ready(ctx->m2m_ctx) < needed)
-		return 0;
-
-	if (v4l2_m2m_num_dst_bufs_ready(ctx->m2m_ctx) < needed)
+	/*
+	 * This check is needed as this might be called directly from driver
+	 * When called by m2m framework, this will always satisy, but when
+	 * called from vpe_irq, this might fail. (src stream with zero buffers)
+	 */
+	if (v4l2_m2m_num_src_bufs_ready(ctx->m2m_ctx) <= 0 ||
+		v4l2_m2m_num_dst_bufs_ready(ctx->m2m_ctx) <= 0)
 		return 0;
 
 	return 1;
@@ -1124,19 +1123,20 @@  static void device_run(void *priv)
 	struct sc_data *sc = ctx->dev->sc;
 	struct vpe_q_data *d_q_data = &ctx->q_data[Q_DATA_DST];
 
-	if (ctx->deinterlacing && ctx->src_vbs[2] == NULL) {
-		ctx->src_vbs[2] = v4l2_m2m_src_buf_remove(ctx->m2m_ctx);
-		WARN_ON(ctx->src_vbs[2] == NULL);
-		ctx->src_vbs[1] = v4l2_m2m_src_buf_remove(ctx->m2m_ctx);
-		WARN_ON(ctx->src_vbs[1] == NULL);
-	}
-
 	ctx->src_vbs[0] = v4l2_m2m_src_buf_remove(ctx->m2m_ctx);
 	WARN_ON(ctx->src_vbs[0] == NULL);
 	ctx->dst_vb = v4l2_m2m_dst_buf_remove(ctx->m2m_ctx);
 	WARN_ON(ctx->dst_vb == NULL);
 
 	if (ctx->deinterlacing) {
+
+		if (ctx->src_vbs[2] == NULL) {
+			ctx->src_vbs[2] = ctx->src_vbs[0];
+			WARN_ON(ctx->src_vbs[2] == NULL);
+			ctx->src_vbs[1] = ctx->src_vbs[0];
+			WARN_ON(ctx->src_vbs[1] == NULL);
+		}
+
 		/*
 		 * we have output the first 2 frames through line average, we
 		 * now switch to EDI de-interlacer
@@ -1360,7 +1360,7 @@  static irqreturn_t vpe_irq(int irq_vpe, void *data)
 	}
 
 	ctx->bufs_completed++;
-	if (ctx->bufs_completed < ctx->bufs_per_job) {
+	if (ctx->bufs_completed < ctx->bufs_per_job && job_ready(ctx)) {
 		device_run(ctx);
 		goto handled;
 	}