Re: [DKIM] [PATCH v21 4/4] media: platform: mtk-mdp3: add Mediatek MDP3 driver

[moudy.ho <moudy.ho@mediatek.com>]

Hi Hans,

Thanks for your review, and appreciate for all comments and
suggestions.
I'll go through each "dev_info" one by one and replace the unnecessary
with "dev_dbg" or just remove it.
In addition, I will adjust other inappropriate settings as suggested.

On Fri, 2022-07-08 at 10:08 +0200, Hans Verkuil wrote:
> Hi Moudy,
> 
> Some comments below:
> 
> On 7/6/22 09:54, Moudy Ho wrote:
> > This patch adds driver for Mediatek's Media Data Path ver.3 (MDP3).
> > It provides the following functions:
> >   color transform, format conversion, resize, crop, rotate, flip
> >   and additional image quality enhancement.
> > 
> > The MDP3 driver is mainly used for Google Chromebook products to
> > import the new architecture to set the HW settings as shown below:
> >   User -> V4L2 framework
> >     -> MDP3 driver -> SCP (setting calculations)
> >       -> MDP3 driver -> CMDQ (GCE driver) -> HW
> > 
> > Each modules' related operation control is sited in mtk-mdp3-comp.c
> > Each modules' register table is defined in file with "mdp_reg_"
> > prefix
> > GCE related API, operation control  sited in mtk-mdp3-cmdq.c
> > V4L2 m2m device functions are implemented in mtk-mdp3-m2m.c
> > Probe, power, suspend/resume, system level functions are defined in
> > mtk-mdp3-core.c
> > 
> > v4l2-compliance 1.22.1, 32 bits, 32-bit time_t
> > 
> > Compliance test for mtk-mdp3 device /dev/video2:
> > 
> > Driver Info:
> > 	Driver name      : mtk-mdp3
> > 	Card type        : 14001000.mdp3-rdma0
> 
> Card type is expected to be a human readable name, and that's not the
> case
> here.
> 
> > 	Bus info         : platform:mtk-mdp3
> 
> <snip>

[snip]

> > diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c
> > b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c
> > new file mode 100644
> > index 000000000000..18874eb7851c
> > --- /dev/null
> > +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c

[snip]

> > +/* Plane size that is accepted by MDP HW */
> > +static u32 mdp_fmt_get_plane_size(const struct mdp_format *fmt,
> > +				  u32 stride, u32 height, unsigned int
> > plane)
> > +{
> > +	enum mdp_color c = fmt->mdp_color;
> > +	u32 bytesperline;
> > +
> > +	bytesperline = (stride * fmt->row_depth[0])
> > +		/ MDP_COLOR_BITS_PER_PIXEL(c);
> > +	if (plane == 0)
> > +		return bytesperline * height;
> > +	if (plane < MDP_COLOR_GET_PLANE_COUNT(c)) {
> > +		height = height >> MDP_COLOR_GET_V_SUBSAMPLE(c);
> > +		if (MDP_COLOR_IS_BLOCK_MODE(c))
> > +			bytesperline = bytesperline * 2;
> > +		return bytesperline * height;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static void mdp_prepare_buffer(struct img_image_buffer *b,
> > +			       struct mdp_frame *frame, struct
> > vb2_buffer *vb)
> > +{
> > +	struct v4l2_pix_format_mplane *pix_mp = &frame-
> > >format.fmt.pix_mp;
> > +	unsigned int i;
> > +
> > +	b->format.colorformat = frame->mdp_fmt->mdp_color;
> > +	b->format.ycbcr_prof = frame->ycbcr_prof;
> > +	for (i = 0; i < pix_mp->num_planes; ++i) {
> > +		u32 stride = mdp_fmt_get_stride(frame->mdp_fmt,
> > +			pix_mp->plane_fmt[i].bytesperline, i);
> > +
> > +		b->format.plane_fmt[i].stride = stride;
> > +		/*
> > +		 * TODO : The way to pass an offset within a DMA-buf
> > +		 * is not defined in V4L2 specification, so we abuse
> > +		 * data_offset for now. Fix it when we have the right
> > interface,
> > +		 * including any necessary validation and potential
> > alignment
> > +		 * issues.
> > +		 */
> > +		b->format.plane_fmt[i].size =
> > +			mdp_fmt_get_plane_size(frame->mdp_fmt, stride,
> > +					       pix_mp->height, i) -
> > +					       vb-
> > >planes[i].data_offset;
> > +		b->iova[i] = vb2_dma_contig_plane_dma_addr(vb, i) +
> > +			     vb->planes[i].data_offset;
> 
> Why do you need data_offset? What is the use case? Obviously I can't
> merge a driver that abuses an API.
> 

Apologize for not incorporating the previously discussed results into
this version due to my carelessness, I will correct it in the next
version.

https://patchwork.kernel.org/project/linux-mediatek/patch/20210623091457.18002-1-moudy.ho@mediatek.com/

> > +	}
> > +	for (; i < MDP_COLOR_GET_PLANE_COUNT(b->format.colorformat);
> > ++i) {
> > +		u32 stride = mdp_fmt_get_stride_contig(frame->mdp_fmt,
> > +			b->format.plane_fmt[0].stride, i);
> > +
> > +		b->format.plane_fmt[i].stride = stride;
> > +		b->format.plane_fmt[i].size =
> > +			mdp_fmt_get_plane_size(frame->mdp_fmt, stride,
> > +					       pix_mp->height, i);
> > +		b->iova[i] = b->iova[i - 1] + b->format.plane_fmt[i -
> > 1].size;
> > +	}
> > +	b->usage = frame->usage;
> > +}
> > +
> > +void mdp_set_src_config(struct img_input *in,
> > +			struct mdp_frame *frame, struct vb2_buffer *vb)
> > +{
> > +	in->buffer.format.width = frame->format.fmt.pix_mp.width;
> > +	in->buffer.format.height = frame->format.fmt.pix_mp.height;
> > +	mdp_prepare_buffer(&in->buffer, frame, vb);
> > +}

[snip]

> 
> Regards,
> 
> 	Hans

Many thanks,
Moudy


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