diff mbox series

media: amphion: ensure the buffer count is not less than min_buffer

Message ID 20220322082859.9834-1-ming.qian@nxp.com (mailing list archive)
State New, archived
Headers show
Series media: amphion: ensure the buffer count is not less than min_buffer | expand

Commit Message

Ming Qian March 22, 2022, 8:28 a.m. UTC
the output buffer count should >= min_buffer_out
the capture buffer count should >= min_buffer_cap

Signed-off-by: Ming Qian <ming.qian@nxp.com>
---
 drivers/media/platform/amphion/vpu_v4l2.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Hans Verkuil April 27, 2022, 6:38 a.m. UTC | #1
Hi Ming Qian,

On 22/03/2022 09:28, Ming Qian wrote:
> the output buffer count should >= min_buffer_out
> the capture buffer count should >= min_buffer_cap
> 
> Signed-off-by: Ming Qian <ming.qian@nxp.com>
> ---
>  drivers/media/platform/amphion/vpu_v4l2.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/media/platform/amphion/vpu_v4l2.c b/drivers/media/platform/amphion/vpu_v4l2.c
> index cbf3315605a9..72a0544f4da3 100644
> --- a/drivers/media/platform/amphion/vpu_v4l2.c
> +++ b/drivers/media/platform/amphion/vpu_v4l2.c
> @@ -355,6 +355,10 @@ static int vpu_vb2_queue_setup(struct vb2_queue *vq,
>  		return 0;
>  	}
>  
> +	if (V4L2_TYPE_IS_OUTPUT(vq->type))
> +		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_out);
> +	else
> +		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_cap);

I noticed that min_buffer_out/cap is set to 2, but min_buffers_needed
is set to 1. Wouldn't it make more sense to set min_buffers_needed to
2 as well?

If you do that, then the vb2 core will already take care of ensuring that
the buf_count is adjusted.

If you *do* have to do this manually, then you need to place the whole
if-else under 'if (!*num_planes) {', otherwise it will mess up the
VIDIOC_CREATE_BUFS ioctl. See the queue_setup in include/media/videobuf2-core.h
documentation for the sordid details.

Regards,

	Hans

>  	*plane_count = cur_fmt->num_planes;
>  	for (i = 0; i < cur_fmt->num_planes; i++)
>  		psize[i] = cur_fmt->sizeimage[i];
Ming Qian April 27, 2022, 7:01 a.m. UTC | #2
> From: Hans Verkuil [mailto:hverkuil-cisco@xs4all.nl]
> Sent: Wednesday, April 27, 2022 2:38 PM
> To: Ming Qian <ming.qian@nxp.com>; mchehab@kernel.org;
> shawnguo@kernel.org
> Cc: robh+dt@kernel.org; s.hauer@pengutronix.de; kernel@pengutronix.de;
> festevam@gmail.com; dl-linux-imx <linux-imx@nxp.com>; Aisheng Dong
> <aisheng.dong@nxp.com>; linux-media@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> Subject: [EXT] Re: [PATCH] media: amphion: ensure the buffer count is not less
> than min_buffer
> 
> Caution: EXT Email
> 
> Hi Ming Qian,
> 
> On 22/03/2022 09:28, Ming Qian wrote:
> > the output buffer count should >= min_buffer_out the capture buffer
> > count should >= min_buffer_cap
> >
> > Signed-off-by: Ming Qian <ming.qian@nxp.com>
> > ---
> >  drivers/media/platform/amphion/vpu_v4l2.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/media/platform/amphion/vpu_v4l2.c
> > b/drivers/media/platform/amphion/vpu_v4l2.c
> > index cbf3315605a9..72a0544f4da3 100644
> > --- a/drivers/media/platform/amphion/vpu_v4l2.c
> > +++ b/drivers/media/platform/amphion/vpu_v4l2.c
> > @@ -355,6 +355,10 @@ static int vpu_vb2_queue_setup(struct vb2_queue
> *vq,
> >               return 0;
> >       }
> >
> > +     if (V4L2_TYPE_IS_OUTPUT(vq->type))
> > +             *buf_count = max_t(unsigned int, *buf_count,
> inst->min_buffer_out);
> > +     else
> > +             *buf_count = max_t(unsigned int, *buf_count,
> > + inst->min_buffer_cap);
> 
> I noticed that min_buffer_out/cap is set to 2, but min_buffers_needed is set to
> 1. Wouldn't it make more sense to set min_buffers_needed to
> 2 as well?
> 
> If you do that, then the vb2 core will already take care of ensuring that the
> buf_count is adjusted.
> 
> If you *do* have to do this manually, then you need to place the whole if-else
> under 'if (!*num_planes) {', otherwise it will mess up the VIDIOC_CREATE_BUFS
> ioctl. See the queue_setup in include/media/videobuf2-core.h documentation
> for the sordid details.
> 
> Regards,
> 
>         Hans
> 

Hi Hans,
    I want to make the vpu start when 1 frames is queued, so I set the min_buffers_needed to 1.
And the min_buffer_cap may be changed when a source change event is triggered. So in most case, it will be larger than 2.
    I'll make a v2 patch that place the whole if-else under 'if (!*num_planes) {'
    Thanks for your reminder

Ming

> >       *plane_count = cur_fmt->num_planes;
> >       for (i = 0; i < cur_fmt->num_planes; i++)
> >               psize[i] = cur_fmt->sizeimage[i];
Hans Verkuil April 27, 2022, 7:25 a.m. UTC | #3
On 27/04/2022 09:01, Ming Qian wrote:
>> From: Hans Verkuil [mailto:hverkuil-cisco@xs4all.nl]
>> Sent: Wednesday, April 27, 2022 2:38 PM
>> To: Ming Qian <ming.qian@nxp.com>; mchehab@kernel.org;
>> shawnguo@kernel.org
>> Cc: robh+dt@kernel.org; s.hauer@pengutronix.de; kernel@pengutronix.de;
>> festevam@gmail.com; dl-linux-imx <linux-imx@nxp.com>; Aisheng Dong
>> <aisheng.dong@nxp.com>; linux-media@vger.kernel.org;
>> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
>> Subject: [EXT] Re: [PATCH] media: amphion: ensure the buffer count is not less
>> than min_buffer
>>
>> Caution: EXT Email
>>
>> Hi Ming Qian,
>>
>> On 22/03/2022 09:28, Ming Qian wrote:
>>> the output buffer count should >= min_buffer_out the capture buffer
>>> count should >= min_buffer_cap
>>>
>>> Signed-off-by: Ming Qian <ming.qian@nxp.com>
>>> ---
>>>  drivers/media/platform/amphion/vpu_v4l2.c | 4 ++++
>>>  1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/media/platform/amphion/vpu_v4l2.c
>>> b/drivers/media/platform/amphion/vpu_v4l2.c
>>> index cbf3315605a9..72a0544f4da3 100644
>>> --- a/drivers/media/platform/amphion/vpu_v4l2.c
>>> +++ b/drivers/media/platform/amphion/vpu_v4l2.c
>>> @@ -355,6 +355,10 @@ static int vpu_vb2_queue_setup(struct vb2_queue
>> *vq,
>>>               return 0;
>>>       }
>>>
>>> +     if (V4L2_TYPE_IS_OUTPUT(vq->type))
>>> +             *buf_count = max_t(unsigned int, *buf_count,
>> inst->min_buffer_out);
>>> +     else
>>> +             *buf_count = max_t(unsigned int, *buf_count,
>>> + inst->min_buffer_cap);
>>
>> I noticed that min_buffer_out/cap is set to 2, but min_buffers_needed is set to
>> 1. Wouldn't it make more sense to set min_buffers_needed to
>> 2 as well?
>>
>> If you do that, then the vb2 core will already take care of ensuring that the
>> buf_count is adjusted.
>>
>> If you *do* have to do this manually, then you need to place the whole if-else
>> under 'if (!*num_planes) {', otherwise it will mess up the VIDIOC_CREATE_BUFS
>> ioctl. See the queue_setup in include/media/videobuf2-core.h documentation
>> for the sordid details.
>>
>> Regards,
>>
>>         Hans
>>
> 
> Hi Hans,
>     I want to make the vpu start when 1 frames is queued, so I set the min_buffers_needed to 1.
> And the min_buffer_cap may be changed when a source change event is triggered. So in most case, it will be larger than 2.

Ah, I only grepped for min_buffer_out, not _cap, so I missed that that one isn't constant.

>     I'll make a v2 patch that place the whole if-else under 'if (!*num_planes) {'

Great, thank you!

	Hans

>     Thanks for your reminder
> 
> Ming
> 
>>>       *plane_count = cur_fmt->num_planes;
>>>       for (i = 0; i < cur_fmt->num_planes; i++)
>>>               psize[i] = cur_fmt->sizeimage[i];
>
Ming Qian April 27, 2022, 9:31 a.m. UTC | #4
> From: Hans Verkuil [mailto:hverkuil-cisco@xs4all.nl]
> Sent: Wednesday, April 27, 2022 3:25 PM
> To: Ming Qian <ming.qian@nxp.com>; mchehab@kernel.org;
> shawnguo@kernel.org
> Cc: robh+dt@kernel.org; s.hauer@pengutronix.de; kernel@pengutronix.de;
> festevam@gmail.com; dl-linux-imx <linux-imx@nxp.com>; Aisheng Dong
> <aisheng.dong@nxp.com>; linux-media@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> Subject: Re: [EXT] Re: [PATCH] media: amphion: ensure the buffer count is not
> less than min_buffer
> 
> Caution: EXT Email
> 
> On 27/04/2022 09:01, Ming Qian wrote:
> >> From: Hans Verkuil [mailto:hverkuil-cisco@xs4all.nl]
> >> Sent: Wednesday, April 27, 2022 2:38 PM
> >> To: Ming Qian <ming.qian@nxp.com>; mchehab@kernel.org;
> >> shawnguo@kernel.org
> >> Cc: robh+dt@kernel.org; s.hauer@pengutronix.de;
> >> kernel@pengutronix.de; festevam@gmail.com; dl-linux-imx
> >> <linux-imx@nxp.com>; Aisheng Dong <aisheng.dong@nxp.com>;
> >> linux-media@vger.kernel.org; linux-kernel@vger.kernel.org;
> >> linux-arm-kernel@lists.infradead.org
> >> Subject: [EXT] Re: [PATCH] media: amphion: ensure the buffer count is
> >> not less than min_buffer
> >>
> >> Caution: EXT Email
> >>
> >> Hi Ming Qian,
> >>
> >> On 22/03/2022 09:28, Ming Qian wrote:
> >>> the output buffer count should >= min_buffer_out the capture buffer
> >>> count should >= min_buffer_cap
> >>>
> >>> Signed-off-by: Ming Qian <ming.qian@nxp.com>
> >>> ---
> >>>  drivers/media/platform/amphion/vpu_v4l2.c | 4 ++++
> >>>  1 file changed, 4 insertions(+)
> >>>
> >>> diff --git a/drivers/media/platform/amphion/vpu_v4l2.c
> >>> b/drivers/media/platform/amphion/vpu_v4l2.c
> >>> index cbf3315605a9..72a0544f4da3 100644
> >>> --- a/drivers/media/platform/amphion/vpu_v4l2.c
> >>> +++ b/drivers/media/platform/amphion/vpu_v4l2.c
> >>> @@ -355,6 +355,10 @@ static int vpu_vb2_queue_setup(struct
> vb2_queue
> >> *vq,
> >>>               return 0;
> >>>       }
> >>>
> >>> +     if (V4L2_TYPE_IS_OUTPUT(vq->type))
> >>> +             *buf_count = max_t(unsigned int, *buf_count,
> >> inst->min_buffer_out);
> >>> +     else
> >>> +             *buf_count = max_t(unsigned int, *buf_count,
> >>> + inst->min_buffer_cap);
> >>
> >> I noticed that min_buffer_out/cap is set to 2, but min_buffers_needed
> >> is set to 1. Wouldn't it make more sense to set min_buffers_needed to
> >> 2 as well?
> >>
> >> If you do that, then the vb2 core will already take care of ensuring
> >> that the buf_count is adjusted.
> >>
> >> If you *do* have to do this manually, then you need to place the
> >> whole if-else under 'if (!*num_planes) {', otherwise it will mess up
> >> the VIDIOC_CREATE_BUFS ioctl. See the queue_setup in
> >> include/media/videobuf2-core.h documentation for the sordid details.
> >>
> >> Regards,
> >>
> >>         Hans
> >>
> >
> > Hi Hans,
> >     I want to make the vpu start when 1 frames is queued, so I set the
> min_buffers_needed to 1.
> > And the min_buffer_cap may be changed when a source change event is
> triggered. So in most case, it will be larger than 2.
> 
> Ah, I only grepped for min_buffer_out, not _cap, so I missed that that one isn't
> constant.
> 
> >     I'll make a v2 patch that place the whole if-else under 'if (!*num_planes)
> {'
>
Hi Hans,
    I send a v2 patch. 
	But I think the v1 is OK, as the full code has already guaranteed the condition ` if (!*num_planes)`,

	if (*plane_count) {
		... ...
		return 0;
    }
 	if (V4L2_TYPE_IS_OUTPUT(vq->type))
		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_out);
	else
		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_cap);

Ming

> Great, thank you!
> 
>         Hans
> 
> >     Thanks for your reminder
> >
> > Ming
> >
> >>>       *plane_count = cur_fmt->num_planes;
> >>>       for (i = 0; i < cur_fmt->num_planes; i++)
> >>>               psize[i] = cur_fmt->sizeimage[i];
> >
Hans Verkuil April 28, 2022, 7:59 a.m. UTC | #5
On 27/04/2022 11:31, Ming Qian wrote:
>> From: Hans Verkuil [mailto:hverkuil-cisco@xs4all.nl]
>> Sent: Wednesday, April 27, 2022 3:25 PM
>> To: Ming Qian <ming.qian@nxp.com>; mchehab@kernel.org;
>> shawnguo@kernel.org
>> Cc: robh+dt@kernel.org; s.hauer@pengutronix.de; kernel@pengutronix.de;
>> festevam@gmail.com; dl-linux-imx <linux-imx@nxp.com>; Aisheng Dong
>> <aisheng.dong@nxp.com>; linux-media@vger.kernel.org;
>> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
>> Subject: Re: [EXT] Re: [PATCH] media: amphion: ensure the buffer count is not
>> less than min_buffer
>>
>> Caution: EXT Email
>>
>> On 27/04/2022 09:01, Ming Qian wrote:
>>>> From: Hans Verkuil [mailto:hverkuil-cisco@xs4all.nl]
>>>> Sent: Wednesday, April 27, 2022 2:38 PM
>>>> To: Ming Qian <ming.qian@nxp.com>; mchehab@kernel.org;
>>>> shawnguo@kernel.org
>>>> Cc: robh+dt@kernel.org; s.hauer@pengutronix.de;
>>>> kernel@pengutronix.de; festevam@gmail.com; dl-linux-imx
>>>> <linux-imx@nxp.com>; Aisheng Dong <aisheng.dong@nxp.com>;
>>>> linux-media@vger.kernel.org; linux-kernel@vger.kernel.org;
>>>> linux-arm-kernel@lists.infradead.org
>>>> Subject: [EXT] Re: [PATCH] media: amphion: ensure the buffer count is
>>>> not less than min_buffer
>>>>
>>>> Caution: EXT Email
>>>>
>>>> Hi Ming Qian,
>>>>
>>>> On 22/03/2022 09:28, Ming Qian wrote:
>>>>> the output buffer count should >= min_buffer_out the capture buffer
>>>>> count should >= min_buffer_cap
>>>>>
>>>>> Signed-off-by: Ming Qian <ming.qian@nxp.com>
>>>>> ---
>>>>>  drivers/media/platform/amphion/vpu_v4l2.c | 4 ++++
>>>>>  1 file changed, 4 insertions(+)
>>>>>
>>>>> diff --git a/drivers/media/platform/amphion/vpu_v4l2.c
>>>>> b/drivers/media/platform/amphion/vpu_v4l2.c
>>>>> index cbf3315605a9..72a0544f4da3 100644
>>>>> --- a/drivers/media/platform/amphion/vpu_v4l2.c
>>>>> +++ b/drivers/media/platform/amphion/vpu_v4l2.c
>>>>> @@ -355,6 +355,10 @@ static int vpu_vb2_queue_setup(struct
>> vb2_queue
>>>> *vq,
>>>>>               return 0;
>>>>>       }
>>>>>
>>>>> +     if (V4L2_TYPE_IS_OUTPUT(vq->type))
>>>>> +             *buf_count = max_t(unsigned int, *buf_count,
>>>> inst->min_buffer_out);
>>>>> +     else
>>>>> +             *buf_count = max_t(unsigned int, *buf_count,
>>>>> + inst->min_buffer_cap);
>>>>
>>>> I noticed that min_buffer_out/cap is set to 2, but min_buffers_needed
>>>> is set to 1. Wouldn't it make more sense to set min_buffers_needed to
>>>> 2 as well?
>>>>
>>>> If you do that, then the vb2 core will already take care of ensuring
>>>> that the buf_count is adjusted.
>>>>
>>>> If you *do* have to do this manually, then you need to place the
>>>> whole if-else under 'if (!*num_planes) {', otherwise it will mess up
>>>> the VIDIOC_CREATE_BUFS ioctl. See the queue_setup in
>>>> include/media/videobuf2-core.h documentation for the sordid details.
>>>>
>>>> Regards,
>>>>
>>>>         Hans
>>>>
>>>
>>> Hi Hans,
>>>     I want to make the vpu start when 1 frames is queued, so I set the
>> min_buffers_needed to 1.
>>> And the min_buffer_cap may be changed when a source change event is
>> triggered. So in most case, it will be larger than 2.
>>
>> Ah, I only grepped for min_buffer_out, not _cap, so I missed that that one isn't
>> constant.
>>
>>>     I'll make a v2 patch that place the whole if-else under 'if (!*num_planes)
>> {'
>>
> Hi Hans,
>     I send a v2 patch. 
> 	But I think the v1 is OK, as the full code has already guaranteed the condition ` if (!*num_planes)`,
> 
> 	if (*plane_count) {
> 		... ...
> 		return 0;
>     }
>  	if (V4L2_TYPE_IS_OUTPUT(vq->type))
> 		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_out);
> 	else
> 		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_cap);
> 

You are correct, it wasn't visible in the patch that the *buf_count adjustments
only happened if *plane_count == 0.

I'm going back to v1.

Sorry for the confusion!

	Hans

> Ming
> 
>> Great, thank you!
>>
>>         Hans
>>
>>>     Thanks for your reminder
>>>
>>> Ming
>>>
>>>>>       *plane_count = cur_fmt->num_planes;
>>>>>       for (i = 0; i < cur_fmt->num_planes; i++)
>>>>>               psize[i] = cur_fmt->sizeimage[i];
>>>
>
diff mbox series

Patch

diff --git a/drivers/media/platform/amphion/vpu_v4l2.c b/drivers/media/platform/amphion/vpu_v4l2.c
index cbf3315605a9..72a0544f4da3 100644
--- a/drivers/media/platform/amphion/vpu_v4l2.c
+++ b/drivers/media/platform/amphion/vpu_v4l2.c
@@ -355,6 +355,10 @@  static int vpu_vb2_queue_setup(struct vb2_queue *vq,
 		return 0;
 	}
 
+	if (V4L2_TYPE_IS_OUTPUT(vq->type))
+		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_out);
+	else
+		*buf_count = max_t(unsigned int, *buf_count, inst->min_buffer_cap);
 	*plane_count = cur_fmt->num_planes;
 	for (i = 0; i < cur_fmt->num_planes; i++)
 		psize[i] = cur_fmt->sizeimage[i];