diff mbox

[2/5] media: vb2: Fix a bug about unnecessary calls to queue cancel and free

Message ID 73a2a81d072b56ab25b36c0f40515d83ef45fccc.1514478428.git.mchehab@s-opensource.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mauro Carvalho Chehab Dec. 28, 2017, 4:29 p.m. UTC 
From: Satendra Singh Thakur <satendra.t@samsung.com>

Currently, there's a logic with checks if *count is non-zero,
q->num_buffers is zero and q->memory is different than memory.

That's flawed when the device is initialized, or after the
queues are freed, as it does, unnecessary calls to
__vb2_queue_cancel() and  __vb2_queue_free().

That can be avoided by making sure that q->memory is set to
VB2_MEMORY_UNKNOWN at vb2_core_queue_init(), and adding such
check at the loop.

[mchehab@s-opensource.com: fix checkpatch issues and improve the
 patch, by setting q->memory to zero at vb2_core_queue_init]
Signed-off-by: Satendra Singh Thakur <satendra.t@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
 drivers/media/common/videobuf/videobuf2-core.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

Sakari Ailus Dec. 28, 2017, 6:24 p.m. UTC | #1 
On Thu, Dec 28, 2017 at 02:29:35PM -0200, Mauro Carvalho Chehab wrote:
> From: Satendra Singh Thakur <satendra.t@samsung.com>
> 
> Currently, there's a logic with checks if *count is non-zero,
> q->num_buffers is zero and q->memory is different than memory.
> 
> That's flawed when the device is initialized, or after the
> queues are freed, as it does, unnecessary calls to
> __vb2_queue_cancel() and  __vb2_queue_free().
> 
> That can be avoided by making sure that q->memory is set to
> VB2_MEMORY_UNKNOWN at vb2_core_queue_init(), and adding such
> check at the loop.
> 
> [mchehab@s-opensource.com: fix checkpatch issues and improve the
>  patch, by setting q->memory to zero at vb2_core_queue_init]
> Signed-off-by: Satendra Singh Thakur <satendra.t@samsung.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
diff mbox

Patch

diff --git a/drivers/media/common/videobuf/videobuf2-core.c b/drivers/media/common/videobuf/videobuf2-core.c
index a3b4836fc41d..1793bdb1fe54 100644
--- a/drivers/media/common/videobuf/videobuf2-core.c
+++ b/drivers/media/common/videobuf/videobuf2-core.c
@@ -523,7 +523,7 @@  static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 
 	q->num_buffers -= buffers;
 	if (!q->num_buffers) {
-		q->memory = 0;
+		q->memory = VB2_MEMORY_UNKNOWN;
 		INIT_LIST_HEAD(&q->queued_list);
 	}
 	return 0;
@@ -665,7 +665,8 @@  int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 		return -EBUSY;
 	}
 
-	if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
+	if (*count == 0 || q->num_buffers != 0 ||
+	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
 		/*
 		 * We already have buffers allocated, so first check if they
 		 * are not in use and can be freed.
@@ -1997,6 +1998,8 @@  int vb2_core_queue_init(struct vb2_queue *q)
 	mutex_init(&q->mmap_lock);
 	init_waitqueue_head(&q->done_wq);
 
+	q->memory = VB2_MEMORY_UNKNOWN;
+
 	if (q->buf_struct_size == 0)
 		q->buf_struct_size = sizeof(struct vb2_buffer);