Hi Kieran,
On Tue, Aug 28, 2018 at 04:26:43PM +0100, Kieran Bingham wrote:
> Hi Jacopo,
>
> Thank you for the patch,
>
>
> On 27/08/18 12:28, Jacopo Mondi wrote:
> > Currently the adv748x driver refuses to probe if both its output endpoints
> > (TXA and TXB) are not connected.
> >
> > Make the driver support probing with (at least) one output endpoint connected
> > and protect the cleanup function from accessing un-initialized fields.
> >
> > Following patches will fix other user of un-initialized TXs in the driver,
> > such as power management functions.
> >
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> > ---
> > drivers/media/i2c/adv748x/adv748x-core.c | 38 +++++++++++++++++++++++++-------
> > drivers/media/i2c/adv748x/adv748x-csi2.c | 17 ++++----------
> > drivers/media/i2c/adv748x/adv748x.h | 2 ++
> > 3 files changed, 36 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
> > index 6ca88daa..78d5996 100644
> > --- a/drivers/media/i2c/adv748x/adv748x-core.c
> > +++ b/drivers/media/i2c/adv748x/adv748x-core.c
> > @@ -654,6 +654,24 @@ static int adv748x_probe(struct i2c_client *client,
> > goto err_cleanup_clients;
> > }
> >
> > + /*
> > + * We can not use container_of to get back to the state with two TXs;
> > + * Initialize the TXs's fields unconditionally on the endpoint
> > + * presence to access them later.
> > + */
> > + state->txa.state = state->txb.state = state;
> > + state->txa.page = ADV748X_PAGE_TXA;
> > + state->txb.page = ADV748X_PAGE_TXB;
> > + state->txa.port = ADV748X_PORT_TXA;
> > + state->txb.port = ADV748X_PORT_TXB;
> > +
>
> Initialising this data here feels a bit hacky...
Possibly, yes.
I'm going to move this back to csi2_init() and call it
unconditionally, but I don't like returning an error if not having a
TX enabled is not an error. I'll go for
if (!is_tx_enabled(tx))
return 0;
>
>
> > + if (!is_tx_enabled(&state->txa) &&
> > + !is_tx_enabled(&state->txb)) {
>
> Could we make is_tx_enabled() based on the information it needs?
>
> is_tx_enabled(ADV748X_PORT_TXA);
>
> Or perhaps:
> is_port_enabled(ADV748X_PORT_TXA)
>
We could, but why? Where's the benefit?
>
> > + ret = -ENODEV;
> > + adv_err(state, "No output endpoint defined\n");
> > + goto err_cleanup_clients;
> > + }
> > +
>
> I approached this slightly differently at [0], by allowing the CSI
> object to initialise, but if they return -ENODEV, then it's fine.
I see. Not my preference actually, but I'll change in v2 as you
suggested above (the tx initialization in csi2_init() )
Thanks
j
>
> The only thing missing from [0] is a check to see if at least one of the
> CSI devices probed.
>
>
>
> You might be interested in [1], from my old 'adv748x/dev' branch [2] for
> looking at the link creation too.
>
> [0]
> https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git/commit/?h=adv748x/for-next&id=ee53e0f7e6e0f3dacc79dcf157ce3c403b17ec14
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git/commit/?h=adv748x/dev&id=e0e975d73a70a5b73ad674e206103cd7df983a04
>
>
> [2]
> https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git/log/?h=adv748x/dev
>
>
> > /* SW reset ADV748X to its default values */
> > ret = adv748x_reset(state);
> > if (ret) {
> > @@ -676,17 +694,21 @@ static int adv748x_probe(struct i2c_client *client,
> > }
> >
> > /* Initialise TXA */
> > - ret = adv748x_csi2_init(state, &state->txa);
> > - if (ret) {
> > - adv_err(state, "Failed to probe TXA");
> > - goto err_cleanup_afe;
> > + if (is_tx_enabled(&state->txa)) {
> > + ret = adv748x_csi2_init(state, &state->txa);
> > + if (ret) {
> > + adv_err(state, "Failed to probe TXA");
> > + goto err_cleanup_afe;
> > + }
> > }
> >
> > /* Initialise TXB */
> > - ret = adv748x_csi2_init(state, &state->txb);
> > - if (ret) {
> > - adv_err(state, "Failed to probe TXB");
> > - goto err_cleanup_txa;
> > + if (is_tx_enabled(&state->txb)) {
> > + ret = adv748x_csi2_init(state, &state->txb);
> > + if (ret) {
> > + adv_err(state, "Failed to probe TXB");
> > + goto err_cleanup_txa;
> > + }
> > }
> >
> > return 0;
> > diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
> > index 469be87..709cdea 100644
> > --- a/drivers/media/i2c/adv748x/adv748x-csi2.c
> > +++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
> > @@ -266,20 +266,8 @@ static int adv748x_csi2_init_controls(struct adv748x_csi2 *tx)
> >
> > int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
> > {
> > - struct device_node *ep;
> > int ret;
> >
> > - /* We can not use container_of to get back to the state with two TXs */
> > - tx->state = state;
> > - tx->page = is_txa(tx) ? ADV748X_PAGE_TXA : ADV748X_PAGE_TXB;
> > -
> > - ep = state->endpoints[is_txa(tx) ? ADV748X_PORT_TXA : ADV748X_PORT_TXB];
> > - if (!ep) {
> > - adv_err(state, "No endpoint found for %s\n",
> > - is_txa(tx) ? "txa" : "txb");
>
> If you used the -ENODEV approach, this adv_err should be removed.
>
> > - return -ENODEV;
> > - }
> > -
> > /* Initialise the virtual channel */
> > adv748x_csi2_set_virtual_channel(tx, 0);
> >
> > @@ -288,7 +276,7 @@ int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
> > is_txa(tx) ? "txa" : "txb");
> >
> > /* Ensure that matching is based upon the endpoint fwnodes */
> > - tx->sd.fwnode = of_fwnode_handle(ep);
> > + tx->sd.fwnode = of_fwnode_handle(state->endpoints[tx->port]);
> >
> > /* Register internal ops for incremental subdev registration */
> > tx->sd.internal_ops = &adv748x_csi2_internal_ops;
> > @@ -321,6 +309,9 @@ int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
> >
> > void adv748x_csi2_cleanup(struct adv748x_csi2 *tx)
> > {
> > + if (!is_tx_enabled(tx))
> > + return;
> > +
> > v4l2_async_unregister_subdev(&tx->sd);
> > media_entity_cleanup(&tx->sd.entity);
> > v4l2_ctrl_handler_free(&tx->ctrl_hdl);
> > diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
> > index 65f8374..1cf46c40 100644
> > --- a/drivers/media/i2c/adv748x/adv748x.h
> > +++ b/drivers/media/i2c/adv748x/adv748x.h
> > @@ -82,6 +82,7 @@ struct adv748x_csi2 {
> > struct adv748x_state *state;
> > struct v4l2_mbus_framefmt format;
> > unsigned int page;
> > + unsigned int port;
> >
> > struct media_pad pads[ADV748X_CSI2_NR_PADS];
> > struct v4l2_ctrl_handler ctrl_hdl;
> > @@ -91,6 +92,7 @@ struct adv748x_csi2 {
> >
> > #define notifier_to_csi2(n) container_of(n, struct adv748x_csi2, notifier)
> > #define adv748x_sd_to_csi2(sd) container_of(sd, struct adv748x_csi2, sd)
> > +#define is_tx_enabled(_tx) ((_tx)->state->endpoints[(_tx)->port] != NULL)
>
> >
> > enum adv748x_hdmi_pads {
> > ADV748X_HDMI_SINK,
> >
>
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