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

[Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx>]

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@xxxxxxxxxxxxx>
> > > CC: Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx>
> > > ---
> > >   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;