Hi Jacopo, Thank you for the patch, On 11/12/2018 15:16, 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. > > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> > --- > drivers/media/i2c/adv748x/adv748x-csi2.c | 48 ++++++++++++++++++++------------ > 1 file changed, 30 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c > index 6ce21542ed48..4d1aefc2c8d0 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 > + * @flags: Flags for the newly created link > * > * 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, > + unsigned int flags) > { > - 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; > - Yup - that part certainly needs to go ... > 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); > + flags); > } > > /* ----------------------------------------------------------------------------- > @@ -68,24 +63,41 @@ 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 HDMI and AFE, 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 the AFE->TXB is. > */ > - 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_txa(tx) && is_afe_enabled(state)) > + if (is_txa(tx)) { > + if (is_hdmi_enabled(state)) { > + ret = adv748x_csi2_register_link(tx, sd->v4l2_dev, > + &state->hdmi.sd, > + ADV748X_HDMI_SOURCE, > + MEDIA_LNK_FL_ENABLED); > + if (ret) > + return ret; > + } > + > + if (is_afe_enabled(state)) { > + ret = adv748x_csi2_register_link(tx, sd->v4l2_dev, > + &state->afe.sd, > + ADV748X_AFE_SOURCE, > + 0); > + if (ret) > + return ret; > + } > + } else if (is_afe_enabled(state)) I believe when adding braces to one side of an if statement, we are supposed to add to the else clauses too ? > return adv748x_csi2_register_link(tx, sd->v4l2_dev, > &state->afe.sd, > - ADV748X_AFE_SOURCE); > + ADV748X_AFE_SOURCE, > + MEDIA_LNK_FL_ENABLED); Won't this enable the AFE link for both TXA and TXB ? Which one will win? Just the last one ? the first one ? Does it error? (It might not be a problem ... I can't recall what the behaviour is) > + There are a lot of nested if's above, and I think we can simplify greatly if we move the logic for the flags inside adv748x_csi2_register_link(), and adjust the checks on is_xxx_enabled() What do you think about the following pseudo code?: int adv748x_csi2_register_link(struct adv748x_csi2 *tx, struct v4l2_device *v4l2_dev, struct v4l2_subdev *src, unsigned int src_pad, bool enable) { int flags = 0; int ret; if (!src->v4l2_dev) { ret = v4l2_device_register_subdev(v4l2_dev, src) if (ret) return ret; } if (enable) flags = MEDIA_LNK_FL_ENABLED; return media_create_pad_link(&src->entity, src_pad, &tx->sd.entity, ADV748X_CSI2_SINK, flags); } int adv748x_csi2_registered(struct v4l2_subdev *sd) { int ret; if (is_afe_enabled(state) { ret = adv748x_csi2_register_link(tx, sd->v4l2_dev, &state->afe.sd, ADV748X_AFE_SOURCE, !is_txa(tx)); if (ret) return ret; } /* TX-B only supports AFE */ if (!is_txa(tx) || !(is_hdmi_enabled(state)) return 0; return adv748x_csi2_register_link(tx, sd->v4l2_dev, &state->hdmi.sd, ADV748X_HDMI_SOURCE, true); } The above will for TXA: register_link(..., AFE_SOURCE, enable = false ); register_link(..., HDMI_SOURCE, enable = true ); then TXB: register_link(..., AFE_SOURCE, enable = true ); Does that meet our needs? > return 0; > } > > -- > 2.7.4 > -- Regards -- Kieran