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From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Hans Verkuil <hverkuil@xs4all.nl>
Cc:     Jacopo Mondi <jacopo+renesas@jmondi.org>, magnus.damm@gmail.com,
        geert@glider.be, mchehab@kernel.org, festevam@gmail.com,
        sakari.ailus@iki.fi, robh+dt@kernel.org, mark.rutland@arm.com,
        pombredanne@nexb.com, linux-renesas-soc@vger.kernel.org,
        linux-media@vger.kernel.org, linux-sh@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 3/9] v4l: platform: Add Renesas CEU driver
Date:   Fri, 19 Jan 2018 14:20:33 +0200
Message-ID: <2529707.jzkV7c2yGz@avalon>
Organization: Ideas on Board Oy
In-Reply-To: <d056343b-46be-436a-e316-0a588a182eb9@xs4all.nl>
References: <1516139101-7835-1-git-send-email-jacopo+renesas@jmondi.org> <1516139101-7835-4-git-send-email-jacopo+renesas@jmondi.org> <d056343b-46be-436a-e316-0a588a182eb9@xs4all.nl>
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Hi Hans,

On Friday, 19 January 2018 13:20:19 EET Hans Verkuil wrote:
> On 01/16/18 22:44, Jacopo Mondi wrote:
> > Add driver for Renesas Capture Engine Unit (CEU).
> > 
> > The CEU interface supports capturing 'data' (YUV422) and 'images'
> > (NV[12|21|16|61]).
> > 
> > This driver aims to replace the soc_camera-based sh_mobile_ceu one.
> > 
> > Tested with ov7670 camera sensor, providing YUYV_2X8 data on Renesas RZ
> > platform GR-Peach.
> > 
> > Tested with ov7725 camera sensor on SH4 platform Migo-R.
> > 
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > 
> >  drivers/media/platform/Kconfig       |    9 +
> >  drivers/media/platform/Makefile      |    1 +
> >  drivers/media/platform/renesas-ceu.c | 1659 +++++++++++++++++++++++++++++
> >  3 files changed, 1669 insertions(+)
> >  create mode 100644 drivers/media/platform/renesas-ceu.c

[snip]

> > diff --git a/drivers/media/platform/renesas-ceu.c
> > b/drivers/media/platform/renesas-ceu.c new file mode 100644
> > index 0000000..1b8f0ef
> > --- /dev/null
> > +++ b/drivers/media/platform/renesas-ceu.c

[snip]

> > +static void ceu_update_plane_sizes(struct v4l2_plane_pix_format *plane,
> > +				   unsigned int bpl, unsigned int szimage)
> > +{
> > +	if (plane->bytesperline < bpl)
> > +		plane->bytesperline = bpl;
> > +	if (plane->sizeimage < szimage)
> > +		plane->sizeimage = szimage;
> 
> As mentioned in your cover letter, you do need to check for invalid
> bytesperline values. The v4l2-compliance test is to see what happens
> when userspace gives insane values, so yes, drivers need to be able
> to handle that.

What limit would you set, what is an acceptable large value versus an invalid 
large value ? I think we should have rules for this at the API level (or at 
least, if not part of the API, rules that are consistent across drivers).

> plane->sizeimage is set by the driver, so drop the 'if' before the
> assignment.

I don't think that's correct. Userspace should be able to control padding 
lines at the end of the image, the same way it controls padding pixels at the 
end of lines.

> > +}

[snip]

> > +static const struct v4l2_ioctl_ops ceu_ioctl_ops = {
> > +	.vidioc_querycap		= ceu_querycap,
> > +
> > +	.vidioc_enum_fmt_vid_cap_mplane	= ceu_enum_fmt_vid_cap,
> > +	.vidioc_try_fmt_vid_cap_mplane	= ceu_try_fmt_vid_cap,
> > +	.vidioc_s_fmt_vid_cap_mplane	= ceu_s_fmt_vid_cap,
> > +	.vidioc_g_fmt_vid_cap_mplane	= ceu_g_fmt_vid_cap,
> > +
> > +	.vidioc_enum_input		= ceu_enum_input,
> > +	.vidioc_g_input			= ceu_g_input,
> > +	.vidioc_s_input			= ceu_s_input,
> > +
> > +	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
> > +	.vidioc_querybuf		= vb2_ioctl_querybuf,
> > +	.vidioc_qbuf			= vb2_ioctl_qbuf,
> > +	.vidioc_expbuf			= vb2_ioctl_expbuf,
> > +	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
> > +	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
> > +	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
> > +	.vidioc_streamon		= vb2_ioctl_streamon,
> > +	.vidioc_streamoff		= vb2_ioctl_streamoff,
> > +
> > +	.vidioc_g_parm			= ceu_g_parm,
> > +	.vidioc_s_parm			= ceu_s_parm,
> > +	.vidioc_enum_framesizes		= ceu_enum_framesizes,
> > +	.vidioc_enum_frameintervals	= ceu_enum_frameintervals,
> 
> You're missing these ioctls:
> 
>         .vidioc_log_status              = v4l2_ctrl_log_status,

Is log status mandatory ?

>         .vidioc_subscribe_event         = v4l2_ctrl_subscribe_event,
>         .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
> 
> These missing _event ops are the reason for this compliance failure:
> 
> fail: v4l2-test-controls.cpp(782): subscribe event for control 'User
> Controls' failed
> > +};

[snip]

-- 
Regards,

Laurent Pinchart