Architectures with non-coherent CPU cache (e.g. ARM) may require a cache
flush or invalidation before starting a hardware operation if the data in
a video buffer being queued has been touched by the CPU.
This patch adds calls to sync before a hardware operation that are expected
to be interpreted and handled by each memory type-specific module.
Whether it is a sync before or after the operation can be determined from
the current buffer state: VIDEOBUF_DONE and VIDEOBUF_ERROR indicate a sync
called after an operation.
Signed-off-by: Pawel Osciak <p.osciak@xxxxxxxxxxx>
Reviewed-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reviewed-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/media/video/videobuf-core.c | 9 +++++++++
drivers/media/video/videobuf-dma-sg.c | 6 ++++++
2 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index bb0a1c8..e56c67a 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -561,6 +561,8 @@ int videobuf_qbuf(struct videobuf_queue *q,
goto done;
}
+ CALL(q, sync, q, buf);
+
list_add_tail(&buf->stream, &q->stream);
if (q->streaming) {
spin_lock_irqsave(q->irqlock, flags);
@@ -761,6 +763,8 @@ static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
if (0 != retval)
goto done;
+ CALL(q, sync, q, q->read_buf);
+
/* start capture & wait */
spin_lock_irqsave(q->irqlock, flags);
q->ops->buf_queue(q, q->read_buf);
@@ -826,6 +830,8 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
goto done;
}
+ CALL(q, sync, q, q->read_buf);
+
spin_lock_irqsave(q->irqlock, flags);
q->ops->buf_queue(q, q->read_buf);
spin_unlock_irqrestore(q->irqlock, flags);
@@ -893,6 +899,9 @@ static int __videobuf_read_start(struct videobuf_queue *q)
err = q->ops->buf_prepare(q, q->bufs[i], field);
if (err)
return err;
+
+ CALL(q, sync, q, q->read_buf);
+
list_add_tail(&q->bufs[i]->stream, &q->stream);
}
spin_lock_irqsave(q->irqlock, flags);
diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c
index fa78555..2b153f8 100644
--- a/drivers/media/video/videobuf-dma-sg.c
+++ b/drivers/media/video/videobuf-dma-sg.c
@@ -50,6 +50,9 @@ MODULE_LICENSE("GPL");
#define dprintk(level, fmt, arg...) if (debug >= level) \
printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
+#define is_sync_after(vb) \
+ (vb->state == VIDEOBUF_DONE || vb->state == VIDEOBUF_ERROR)
+
/* --------------------------------------------------------------------- */
struct scatterlist*
@@ -516,6 +519,9 @@ static int __videobuf_sync(struct videobuf_queue *q,
BUG_ON(!mem);
MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
+ if (!is_sync_after(buf))
+ return 0;
+
return videobuf_dma_sync(q,&mem->dma);
}
--
1.6.4.2.253.g0b1fac
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
