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...
> + 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)
> + 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.
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,
>
