* [PATCH] vb2: clear timestamp if buffer mem is reacquired
@ 2019-02-02 17:03 Hans Verkuil
2019-02-02 20:59 ` Nicolas Dufresne
0 siblings, 1 reply; 3+ messages in thread
From: Hans Verkuil @ 2019-02-02 17:03 UTC (permalink / raw)
To: Linux Media Mailing List, Tomasz Figa, Alexandre Courbot,
Paul Kocialkowski
Stateless codecs have to find buffers based on a timestamp (vb2_find_timestamp).
The timestamp is set to 0 initially, so prohibit finding timestamp 0 since it
could find unused buffers without associated memory (userptr or dmabuf).
The memory associated with a buffer will also disappear if the same buffer was
requeued with a different userptr address or dmabuf fd. Detect this and set the
timestamp of that buffer to 0 if this happens.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
Note: I think it is still necessary to lock a buffer when it is in use as
a reference frame, otherwise a userspace application can queue it again with
a different dmabuf fd, which could free the memory of the old dmabuf.
vb2_find_buffer should probably do that.
---
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index e07b6bdb6982..b664d9790330 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -1043,6 +1043,8 @@ static int __prepare_userptr(struct vb2_buffer *vb)
reacquired = true;
call_void_vb_qop(vb, buf_cleanup, vb);
}
+ if (!q->is_output)
+ vb->timestamp = 0;
call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
}
@@ -1157,6 +1159,8 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
/* Skip the plane if already verified */
if (dbuf == vb->planes[plane].dbuf &&
vb->planes[plane].length == planes[plane].length) {
+ if (!q->is_output)
+ vb->timestamp = 0;
dma_buf_put(dbuf);
continue;
}
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 3aeaea3af42a..8e966fa81b7e 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -603,6 +603,9 @@ int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
{
unsigned int i;
+ if (!timestamp)
+ return -1;
+
for (i = start_idx; i < q->num_buffers; i++)
if (q->bufs[i]->timestamp == timestamp)
return i;
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 8a10889dc2fd..01bf4b2199c7 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -59,14 +59,14 @@ struct vb2_v4l2_buffer {
* vb2_find_timestamp() - Find buffer with given timestamp in the queue
*
* @q: pointer to &struct vb2_queue with videobuf2 queue.
- * @timestamp: the timestamp to find.
+ * @timestamp: the timestamp to find. Must be > 0.
* @start_idx: the start index (usually 0) in the buffer array to start
* searching from. Note that there may be multiple buffers
* with the same timestamp value, so you can restart the search
* by setting @start_idx to the previously found index + 1.
*
* Returns the buffer index of the buffer with the given @timestamp, or
- * -1 if no buffer with @timestamp was found.
+ * -1 if no buffer with @timestamp was found or if @timestamp was 0.
*/
int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
unsigned int start_idx);
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] vb2: clear timestamp if buffer mem is reacquired
2019-02-02 17:03 [PATCH] vb2: clear timestamp if buffer mem is reacquired Hans Verkuil
@ 2019-02-02 20:59 ` Nicolas Dufresne
2019-02-03 8:23 ` Hans Verkuil
0 siblings, 1 reply; 3+ messages in thread
From: Nicolas Dufresne @ 2019-02-02 20:59 UTC (permalink / raw)
To: Hans Verkuil, Linux Media Mailing List, Tomasz Figa,
Alexandre Courbot, Paul Kocialkowski
Le samedi 02 février 2019 à 18:03 +0100, Hans Verkuil a écrit :
> Stateless codecs have to find buffers based on a timestamp (vb2_find_timestamp).
> The timestamp is set to 0 initially, so prohibit finding timestamp 0 since it
> could find unused buffers without associated memory (userptr or dmabuf).
>
> The memory associated with a buffer will also disappear if the same buffer was
> requeued with a different userptr address or dmabuf fd. Detect this and set the
> timestamp of that buffer to 0 if this happens.
Just a small concern, does it mean 0 is considered an invalid timestamp
? In streaming it would be quite normal for a first picture to have PTS
0.
Nicolas
>
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
> Note: I think it is still necessary to lock a buffer when it is in use as
> a reference frame, otherwise a userspace application can queue it again with
> a different dmabuf fd, which could free the memory of the old dmabuf.
>
> vb2_find_buffer should probably do that.
> ---
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index e07b6bdb6982..b664d9790330 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -1043,6 +1043,8 @@ static int __prepare_userptr(struct vb2_buffer *vb)
> reacquired = true;
> call_void_vb_qop(vb, buf_cleanup, vb);
> }
> + if (!q->is_output)
> + vb->timestamp = 0;
> call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
> }
>
> @@ -1157,6 +1159,8 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
> /* Skip the plane if already verified */
> if (dbuf == vb->planes[plane].dbuf &&
> vb->planes[plane].length == planes[plane].length) {
> + if (!q->is_output)
> + vb->timestamp = 0;
> dma_buf_put(dbuf);
> continue;
> }
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 3aeaea3af42a..8e966fa81b7e 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -603,6 +603,9 @@ int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
> {
> unsigned int i;
>
> + if (!timestamp)
> + return -1;
> +
> for (i = start_idx; i < q->num_buffers; i++)
> if (q->bufs[i]->timestamp == timestamp)
> return i;
> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
> index 8a10889dc2fd..01bf4b2199c7 100644
> --- a/include/media/videobuf2-v4l2.h
> +++ b/include/media/videobuf2-v4l2.h
> @@ -59,14 +59,14 @@ struct vb2_v4l2_buffer {
> * vb2_find_timestamp() - Find buffer with given timestamp in the queue
> *
> * @q: pointer to &struct vb2_queue with videobuf2 queue.
> - * @timestamp: the timestamp to find.
> + * @timestamp: the timestamp to find. Must be > 0.
> * @start_idx: the start index (usually 0) in the buffer array to start
> * searching from. Note that there may be multiple buffers
> * with the same timestamp value, so you can restart the search
> * by setting @start_idx to the previously found index + 1.
> *
> * Returns the buffer index of the buffer with the given @timestamp, or
> - * -1 if no buffer with @timestamp was found.
> + * -1 if no buffer with @timestamp was found or if @timestamp was 0.
> */
> int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
> unsigned int start_idx);
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] vb2: clear timestamp if buffer mem is reacquired
2019-02-02 20:59 ` Nicolas Dufresne
@ 2019-02-03 8:23 ` Hans Verkuil
0 siblings, 0 replies; 3+ messages in thread
From: Hans Verkuil @ 2019-02-03 8:23 UTC (permalink / raw)
To: Nicolas Dufresne, Linux Media Mailing List, Tomasz Figa,
Alexandre Courbot, Paul Kocialkowski
On 02/02/2019 09:59 PM, Nicolas Dufresne wrote:
> Le samedi 02 février 2019 à 18:03 +0100, Hans Verkuil a écrit :
>> Stateless codecs have to find buffers based on a timestamp (vb2_find_timestamp).
>> The timestamp is set to 0 initially, so prohibit finding timestamp 0 since it
>> could find unused buffers without associated memory (userptr or dmabuf).
>>
>> The memory associated with a buffer will also disappear if the same buffer was
>> requeued with a different userptr address or dmabuf fd. Detect this and set the
>> timestamp of that buffer to 0 if this happens.
>
> Just a small concern, does it mean 0 is considered an invalid timestamp
> ? In streaming it would be quite normal for a first picture to have PTS
> 0.
Good point. Perhaps I should make ~0ULL the invalid timestamp instead.
I'll look at that tomorrow.
Regards,
Hans
>
> Nicolas
>
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
>> ---
>> Note: I think it is still necessary to lock a buffer when it is in use as
>> a reference frame, otherwise a userspace application can queue it again with
>> a different dmabuf fd, which could free the memory of the old dmabuf.
>>
>> vb2_find_buffer should probably do that.
>> ---
>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>> index e07b6bdb6982..b664d9790330 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>> @@ -1043,6 +1043,8 @@ static int __prepare_userptr(struct vb2_buffer *vb)
>> reacquired = true;
>> call_void_vb_qop(vb, buf_cleanup, vb);
>> }
>> + if (!q->is_output)
>> + vb->timestamp = 0;
>> call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
>> }
>>
>> @@ -1157,6 +1159,8 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
>> /* Skip the plane if already verified */
>> if (dbuf == vb->planes[plane].dbuf &&
>> vb->planes[plane].length == planes[plane].length) {
>> + if (!q->is_output)
>> + vb->timestamp = 0;
>> dma_buf_put(dbuf);
>> continue;
>> }
>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> index 3aeaea3af42a..8e966fa81b7e 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> @@ -603,6 +603,9 @@ int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
>> {
>> unsigned int i;
>>
>> + if (!timestamp)
>> + return -1;
>> +
>> for (i = start_idx; i < q->num_buffers; i++)
>> if (q->bufs[i]->timestamp == timestamp)
>> return i;
>> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
>> index 8a10889dc2fd..01bf4b2199c7 100644
>> --- a/include/media/videobuf2-v4l2.h
>> +++ b/include/media/videobuf2-v4l2.h
>> @@ -59,14 +59,14 @@ struct vb2_v4l2_buffer {
>> * vb2_find_timestamp() - Find buffer with given timestamp in the queue
>> *
>> * @q: pointer to &struct vb2_queue with videobuf2 queue.
>> - * @timestamp: the timestamp to find.
>> + * @timestamp: the timestamp to find. Must be > 0.
>> * @start_idx: the start index (usually 0) in the buffer array to start
>> * searching from. Note that there may be multiple buffers
>> * with the same timestamp value, so you can restart the search
>> * by setting @start_idx to the previously found index + 1.
>> *
>> * Returns the buffer index of the buffer with the given @timestamp, or
>> - * -1 if no buffer with @timestamp was found.
>> + * -1 if no buffer with @timestamp was found or if @timestamp was 0.
>> */
>> int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
>> unsigned int start_idx);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-02-02 17:03 [PATCH] vb2: clear timestamp if buffer mem is reacquired Hans Verkuil
2019-02-02 20:59 ` Nicolas Dufresne
2019-02-03 8:23 ` Hans Verkuil
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