@@ -856,7 +856,7 @@ static int rvin_capture_start(struct rvin_dev *vin)
/* Continuous Frame Capture Mode */
rvin_write(vin, VNFC_C_FRAME, VNFC_REG);
- vin->state = RUNNING;
+ vin->state = STARTING;
return 0;
}
@@ -910,6 +910,20 @@ static irqreturn_t rvin_irq(int irq, void *data)
vnms = rvin_read(vin, VNMS_REG);
slot = (vnms & VNMS_FBS_MASK) >> VNMS_FBS_SHIFT;
+ /*
+ * To hand buffers back in a known order to userspace start
+ * to capture first from slot 0.
+ */
+ if (vin->state == STARTING) {
+ if (slot != 0) {
+ vin_dbg(vin, "Starting sync slot: %d\n", slot);
+ goto done;
+ }
+
+ vin_dbg(vin, "Capture start synced!\n");
+ vin->state = RUNNING;
+ }
+
/* Capture frame */
if (vin->queue_buf[slot]) {
vin->queue_buf[slot]->field = vin->format.field;
@@ -53,11 +53,13 @@ enum rvin_csi_id {
/**
* STOPPED - No operation in progress
+ * STARTING - Capture starting up
* RUNNING - Operation in progress have buffers
* STOPPING - Stopping operation
*/
enum rvin_dma_state {
STOPPED = 0,
+ STARTING,
RUNNING,
STOPPING,
};
When starting the VIN capture procedure we are not guaranteed that the first buffer written to is VnMB1 to which we assigned the first buffer queued. This is problematic for two reasons. Buffers might not be dequeued in the same order they where queued for capture. Future features planed for the VIN driver is support for outputting frames in SEQ_TB/BT format and to do that it's important that capture starts from the first buffer slot, VnMB1. We are guaranteed that capturing always happens in sequence (VnMB1 -> VnMB2 -> VnMB3 -> VnMB1). So drop up to two frames when starting capturing so that the driver always returns buffers in the same order they are queued and prepare for SEQ_TB/BT output. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> --- * Changes since v1 - Fix spelling in commit message pointed out by Sergei. s/writing/written/ and s/outputing/outputting/. --- drivers/media/platform/rcar-vin/rcar-dma.c | 16 +++++++++++++++- drivers/media/platform/rcar-vin/rcar-vin.h | 2 ++ 2 files changed, 17 insertions(+), 1 deletion(-)