Re: [PATCH v15 30/56] media: test-drivers: Stop direct calls to queue num_buffers field

[Andrzej Pietrasiewicz <andrzej.p@collabora.com>]

Hi Benjamin,

W dniu 10.11.2023 o 10:55, Benjamin Gaignard pisze:
> 
> Le 10/11/2023 à 10:35, Andrzej Pietrasiewicz a écrit :
>> Hi Benjamin,
>>
>> W dniu 9.11.2023 o 17:34, Benjamin Gaignard pisze:
>>> Use vb2_get_num_buffers() to avoid using queue num_buffers field directly.
>>> This allows us to change how the number of buffers is computed in the
>>> future.
>>> If 'min_buffers_needed' is set remove useless checks in queue setup
>>> functions.
>>>
>>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
>>> CC: Daniel Almeida <daniel.almeida@collabora.com>
>>> ---
>>>   drivers/media/test-drivers/visl/visl-dec.c         | 4 ++--
>>>   drivers/media/test-drivers/vivid/vivid-meta-cap.c  | 3 ---
>>>   drivers/media/test-drivers/vivid/vivid-meta-out.c  | 5 +++--
>>>   drivers/media/test-drivers/vivid/vivid-touch-cap.c | 5 +++--
>>>   drivers/media/test-drivers/vivid/vivid-vbi-cap.c   | 3 ---
>>>   drivers/media/test-drivers/vivid/vivid-vbi-out.c   | 3 ---
>>>   drivers/media/test-drivers/vivid/vivid-vid-cap.c   | 3 ---
>>>   drivers/media/test-drivers/vivid/vivid-vid-out.c   | 5 +----
>>>   8 files changed, 9 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/drivers/media/test-drivers/visl/visl-dec.c 
>>> b/drivers/media/test-drivers/visl/visl-dec.c
>>> index ba20ea998d19..4672dc5e52bb 100644
>>> --- a/drivers/media/test-drivers/visl/visl-dec.c
>>> +++ b/drivers/media/test-drivers/visl/visl-dec.c
>>> @@ -287,7 +287,7 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct 
>>> visl_run *run)
>>>       frame_dprintk(ctx->dev, run->dst->sequence, "%s\n", buf);
>>>         len = 0;
>>> -    for (i = 0; i < out_q->num_buffers; i++) {
>>> +    for (i = 0; i < vb2_get_num_buffers(out_q); i++) {
>>>           char entry[] = "index: %u, state: %s, request_fd: %d, ";
>>>           u32 old_len = len;
>>>           struct vb2_buffer *vb2;
>>> @@ -347,7 +347,7 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct 
>>> visl_run *run)
>>>       frame_dprintk(ctx->dev, run->dst->sequence, "%s\n", buf);
>>>         len = 0;
>>> -    for (i = 0; i < cap_q->num_buffers; i++) {
>>> +    for (i = 0; i < vb2_get_num_buffers(cap_q); i++) {
>>>           u32 old_len = len;
>>>           struct vb2_buffer *vb2;
>>>           char *q_status;
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-meta-cap.c 
>>> b/drivers/media/test-drivers/vivid/vivid-meta-cap.c
>>> index 780f96860a6d..0a718d037e59 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-meta-cap.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-meta-cap.c
>>> @@ -30,9 +30,6 @@ static int meta_cap_queue_setup(struct vb2_queue *vq, 
>>> unsigned int *nbuffers,
>>>           sizes[0] = size;
>>>       }
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> -
>>>       *nplanes = 1;
>>>       return 0;
>>>   }
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-meta-out.c 
>>> b/drivers/media/test-drivers/vivid/vivid-meta-out.c
>>> index 95835b52b58f..4a569a6e58be 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-meta-out.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-meta-out.c
>>> @@ -18,6 +18,7 @@ static int meta_out_queue_setup(struct vb2_queue *vq, 
>>> unsigned int *nbuffers,
>>>                   struct device *alloc_devs[])
>>>   {
>>>       struct vivid_dev *dev = vb2_get_drv_priv(vq);
>>> +    unsigned int q_num_bufs = vb2_get_num_buffers(vq);
>>>       unsigned int size =  sizeof(struct vivid_meta_out_buf);
>>>         if (!vivid_is_webcam(dev))
>>> @@ -30,8 +31,8 @@ static int meta_out_queue_setup(struct vb2_queue *vq, 
>>> unsigned int *nbuffers,
>>>           sizes[0] = size;
>>>       }
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> +    if (q_num_bufs + *nbuffers < 2)
>>> +        *nbuffers = 2 - q_num_bufs;
>>>         *nplanes = 1;
>>>       return 0;
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-touch-cap.c 
>>> b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
>>> index c7f6e23df51e..4b3c6ea0afde 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-touch-cap.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
>>> @@ -13,6 +13,7 @@ static int touch_cap_queue_setup(struct vb2_queue *vq, 
>>> unsigned int *nbuffers,
>>>                    struct device *alloc_devs[])
>>>   {
>>>       struct vivid_dev *dev = vb2_get_drv_priv(vq);
>>> +    unsigned int q_num_bufs = vb2_get_num_buffers(vq);
>>>       struct v4l2_pix_format *f = &dev->tch_format;
>>>       unsigned int size = f->sizeimage;
>>>   @@ -23,8 +24,8 @@ static int touch_cap_queue_setup(struct vb2_queue *vq, 
>>> unsigned int *nbuffers,
>>>           sizes[0] = size;
>>>       }
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> +    if (q_num_bufs + *nbuffers < 2)
>>> +        *nbuffers = 2 - q_num_bufs;
>>>         *nplanes = 1;
>>>       return 0;
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-vbi-cap.c 
>>> b/drivers/media/test-drivers/vivid/vivid-vbi-cap.c
>>> index b65b02eeeb97..3840b3a664ac 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-vbi-cap.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-vbi-cap.c
>>> @@ -134,9 +134,6 @@ static int vbi_cap_queue_setup(struct vb2_queue *vq,
>>>         sizes[0] = size;
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> -
>>>       *nplanes = 1;
>>>       return 0;
>>>   }
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-vbi-out.c 
>>> b/drivers/media/test-drivers/vivid/vivid-vbi-out.c
>>> index cd56476902a2..434a10676417 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-vbi-out.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-vbi-out.c
>>> @@ -30,9 +30,6 @@ static int vbi_out_queue_setup(struct vb2_queue *vq,
>>>         sizes[0] = size;
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> -
>>>       *nplanes = 1;
>>>       return 0;
>>>   }
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-vid-cap.c 
>>> b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
>>> index 3a06df35a2d7..2804975fe278 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-vid-cap.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
>>> @@ -117,9 +117,6 @@ static int vid_cap_queue_setup(struct vb2_queue *vq,
>>>                       dev->fmt_cap->data_offset[p];
>>>       }
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> -
>>>       *nplanes = buffers;
>>>         dprintk(dev, 1, "%s: count=%d\n", __func__, *nbuffers);
>>
>> here the format specifier for "*nbuffers" is "%d"...
>>
>>> diff --git a/drivers/media/test-drivers/vivid/vivid-vid-out.c 
>>> b/drivers/media/test-drivers/vivid/vivid-vid-out.c
>>> index 184a6df2c29f..1653b2988f7e 100644
>>> --- a/drivers/media/test-drivers/vivid/vivid-vid-out.c
>>> +++ b/drivers/media/test-drivers/vivid/vivid-vid-out.c
>>> @@ -73,12 +73,9 @@ static int vid_out_queue_setup(struct vb2_queue *vq,
>>>                          vfmt->data_offset[p] : size;
>>>       }
>>>   -    if (vq->num_buffers + *nbuffers < 2)
>>> -        *nbuffers = 2 - vq->num_buffers;
>>> -
>>>       *nplanes = planes;
>>>   -    dprintk(dev, 1, "%s: count=%d\n", __func__, *nbuffers);
>>> +    dprintk(dev, 1, "%s: count=%u\n", __func__, *nbuffers);
>>
>> ... but here you change it to "%u". Is there a reason for these two to be
>> different? I didn't notice it in the previous version but now it stands out
>> clearly. Probably you changed to %u because of the type returned by
>> vb2_get_num_buffers(). And, actually, *nbuffers _is_ unsigned, too.
> 
> Like you said *nbuffers is unsigned so %u sound for me.
> The goal of this patch was to avoid vq->num_buffers usage not to clean up all the
> file.
> That could be done in other patch since there is lot to do here.
> 

Arguably, if the purpose of this patch is to avoid using vq->num_buffers,
the line we're discussing could be left unpatched, which minimizes the diffstat.

Otherwise, you _are_ changing vid_cap_queue_setup() anyway.

Regards,

Andrzej

> Regards,
> Benjamin
> 
>>
>> Regards,
>>
>> Andrzej
>>
>>>       for (p = 0; p < planes; p++)
>>>           dprintk(dev, 1, "%s: size[%u]=%u\n", __func__, p, sizes[p]);
>>>       return 0;
>>