Re: [PATCH v3 3/6] media: adv748x: csi2: Link AFE with TXA and TXB

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

On 2019-01-28 15:47:37 +0100, Jacopo Mondi wrote:
> Hi Niklas,
>    sorry for replying late
> 
> On Wed, Jan 16, 2019 at 02:44:25PM +0100, Niklas Söderlund wrote:
> > Hi (again) Jacopo,
> >
> > I found something else in this patch unfortunately :-(
> >
> > On 2019-01-14 15:55:33 +0100, Niklas Söderlund wrote:
> > > Hi Jacopo,
> > >
> > > Thanks for your patch.
> > >
> > > On 2019-01-10 15:02:10 +0100, Jacopo Mondi wrote:
> > > > The ADV748x chip supports routing AFE output to either TXA or TXB.
> > > > In order to support run-time configuration of video stream path, create an
> > > > additional (not enabled) "AFE:8->TXA:0" link, and remove the IMMUTABLE flag
> > > > from existing ones.
> > > >
> > > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > > > ---
> > > >  drivers/media/i2c/adv748x/adv748x-csi2.c | 44 +++++++++++++-----------
> > > >  1 file changed, 23 insertions(+), 21 deletions(-)
> > > >
> > > > diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
> > > > index b6b5d8c7ea7c..8c3714495e11 100644
> > > > --- a/drivers/media/i2c/adv748x/adv748x-csi2.c
> > > > +++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
> > > > @@ -27,6 +27,7 @@ static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
> > > >   * @v4l2_dev: Video registration device
> > > >   * @src: Source subdevice to establish link
> > > >   * @src_pad: Pad number of source to link to this @tx
> > > > + * @enable: Link enabled flag
> > > >   *
> > > >   * Ensure that the subdevice is registered against the v4l2_device, and link the
> > > >   * source pad to the sink pad of the CSI2 bus entity.
> > > > @@ -34,17 +35,11 @@ static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
> > > >  static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
> > > >  				      struct v4l2_device *v4l2_dev,
> > > >  				      struct v4l2_subdev *src,
> > > > -				      unsigned int src_pad)
> > > > +				      unsigned int src_pad,
> > > > +				      bool enable)
> > > >  {
> > > > -	int enabled = MEDIA_LNK_FL_ENABLED;
> > > >  	int ret;
> > > >
> > > > -	/*
> > > > -	 * Dynamic linking of the AFE is not supported.
> > > > -	 * Register the links as immutable.
> > > > -	 */
> > > > -	enabled |= MEDIA_LNK_FL_IMMUTABLE;
> > > > -
> > > >  	if (!src->v4l2_dev) {
> > > >  		ret = v4l2_device_register_subdev(v4l2_dev, src);
> > > >  		if (ret)
> > > > @@ -53,7 +48,7 @@ static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
> > > >
> > > >  	return media_create_pad_link(&src->entity, src_pad,
> > > >  				     &tx->sd.entity, ADV748X_CSI2_SINK,
> > > > -				     enabled);
> > > > +				     enable ? MEDIA_LNK_FL_ENABLED : 0);
> > > >  }
> > > >
> > > >  /* -----------------------------------------------------------------------------
> > > > @@ -68,25 +63,32 @@ static int adv748x_csi2_registered(struct v4l2_subdev *sd)
> > > >  {
> > > >  	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
> > > >  	struct adv748x_state *state = tx->state;
> > > > +	int ret;
> > > >
> > > >  	adv_dbg(state, "Registered %s (%s)", is_txa(tx) ? "TXA":"TXB",
> > > >  			sd->name);
> > > >
> > > >  	/*
> > > > -	 * The adv748x hardware allows the AFE to route through the TXA, however
> > > > -	 * this is not currently supported in this driver.
> > > > +	 * Link TXA to AFE and HDMI, and TXB to AFE only as TXB cannot output
> > > > +	 * HDMI.
> > > >  	 *
> > > > -	 * Link HDMI->TXA, and AFE->TXB directly.
> > > > +	 * The HDMI->TXA link is enabled by default, as is the AFE->TXB one.
> > > >  	 */
> > > > -	if (is_txa(tx) && is_hdmi_enabled(state))
> > > > -		return adv748x_csi2_register_link(tx, sd->v4l2_dev,
> > > > -						  &state->hdmi.sd,
> > > > -						  ADV748X_HDMI_SOURCE);
> > > > -	if (is_txb(tx) && is_afe_enabled(state))
> > > > -		return adv748x_csi2_register_link(tx, sd->v4l2_dev,
> > > > -						  &state->afe.sd,
> > > > -						  ADV748X_AFE_SOURCE);
> > > > -	return 0;
> > > > +	if (is_afe_enabled(state)) {
> > > > +		ret = adv748x_csi2_register_link(tx, sd->v4l2_dev,
> > > > +						 &state->afe.sd,
> > > > +						 ADV748X_AFE_SOURCE,
> > > > +						 is_txb(tx));
> > > > +		if (ret)
> > > > +			return ret;
> > > > +	}
> > > > +
> > > > +	/* Register link to HDMI for TXA only. */
> > > > +	if (is_txb(tx) || !is_hdmi_enabled(state))
> > >
> > > Small nit, I would s/is_txb(tx)/!is_txa(tx)/ here as to me it becomes
> > > easier to read. With or without this change,
> > >
> > > Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > >
> > > > +		return 0;
> > > > +
> > > > +	return adv748x_csi2_register_link(tx, sd->v4l2_dev, &state->hdmi.sd,
> > > > +					  ADV748X_HDMI_SOURCE, true);
> >
> > If the call to adv748x_csi2_register_link() fails should not the
> > (possible) link to the AFE be removed?
> >
> 
> The .register() callback is called from v4l2-device.c in
> v4l2_device_register_subdev(). If the callback returns an error, the
> subdev gets not registered at all and the media entity cleaned up, so it
> won't appear in the media graph.
> 
> I think we're safe and the patch series is good to go. What's your
> opinion?

As long as no stray links are left in the graph I'm happy :-)

> 
> Thanks
>   j
> 
> 
> > > >  }
> > > >
> > > >  static const struct v4l2_subdev_internal_ops adv748x_csi2_internal_ops = {
> > > > --
> > > > 2.20.1
> > > >
> > >
> > > --
> > > Regards,
> > > Niklas Söderlund
> >
> > --
> > Regards,
> > Niklas Söderlund



-- 
Regards,
Niklas Söderlund