On Wed, Mar 27, 2024 at 11:45:53PM +0100, Christian A. Ehrhardt wrote:
> Some PPM implementation do not like UCSI_ACK_CONNECTOR_CHANGE
> without UCSI_ACK_COMMAND_COMPLETE. Moreover, doing this is racy
> as it requires sending two UCSI_ACK_CC_CI commands in a row and
> the second one will be started with UCSI_CCI_ACK_COMPLETE already
> set in CCI.
>
> Bundle the UCSI_ACK_CONNECTOR_CHANGE with the UCSI_ACK_COMMAND_COMPLETE
> for the UCSI_GET_CONNECTOR_STATUS command that is sent while
> handling a connector change event.
>
> Signed-off-by: Christian A. Ehrhardt <lk@xxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/ucsi/ucsi.c | 48 +++++++++++++++--------------------
> 1 file changed, 21 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 31d8a46ae5e7..48f093a1dc09 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -49,22 +49,16 @@ static int ucsi_read_message_in(struct ucsi *ucsi, void *buf,
> return ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, buf, buf_size);
> }
>
> -static int ucsi_acknowledge_command(struct ucsi *ucsi)
> +static int ucsi_acknowledge(struct ucsi *ucsi, bool conn_ack)
> {
> u64 ctrl;
>
> ctrl = UCSI_ACK_CC_CI;
> ctrl |= UCSI_ACK_COMMAND_COMPLETE;
> -
> - return ucsi->ops->sync_write(ucsi, UCSI_CONTROL, &ctrl, sizeof(ctrl));
> -}
> -
> -static int ucsi_acknowledge_connector_change(struct ucsi *ucsi)
> -{
> - u64 ctrl;
> -
> - ctrl = UCSI_ACK_CC_CI;
> - ctrl |= UCSI_ACK_CONNECTOR_CHANGE;
> + if (conn_ack) {
> + clear_bit(EVENT_PENDING, &ucsi->flags);
> + ctrl |= UCSI_ACK_CONNECTOR_CHANGE;
> + }
>
> return ucsi->ops->sync_write(ucsi, UCSI_CONTROL, &ctrl, sizeof(ctrl));
> }
> @@ -77,7 +71,7 @@ static int ucsi_read_error(struct ucsi *ucsi)
> int ret;
>
> /* Acknowledge the command that failed */
> - ret = ucsi_acknowledge_command(ucsi);
> + ret = ucsi_acknowledge(ucsi, false);
> if (ret)
> return ret;
>
> @@ -89,7 +83,7 @@ static int ucsi_read_error(struct ucsi *ucsi)
> if (ret)
> return ret;
>
> - ret = ucsi_acknowledge_command(ucsi);
> + ret = ucsi_acknowledge(ucsi, false);
> if (ret)
> return ret;
>
> @@ -152,7 +146,7 @@ static int ucsi_exec_command(struct ucsi *ucsi, u64 cmd)
> return -EIO;
>
> if (cci & UCSI_CCI_NOT_SUPPORTED) {
> - if (ucsi_acknowledge_command(ucsi) < 0)
> + if (ucsi_acknowledge(ucsi, false) < 0)
> dev_err(ucsi->dev,
> "ACK of unsupported command failed\n");
> return -EOPNOTSUPP;
> @@ -165,15 +159,15 @@ static int ucsi_exec_command(struct ucsi *ucsi, u64 cmd)
> }
>
> if (cmd == UCSI_CANCEL && cci & UCSI_CCI_CANCEL_COMPLETE) {
> - ret = ucsi_acknowledge_command(ucsi);
> + ret = ucsi_acknowledge(ucsi, false);
> return ret ? ret : -EBUSY;
> }
>
> return UCSI_CCI_LENGTH(cci);
> }
>
> -int ucsi_send_command(struct ucsi *ucsi, u64 command,
> - void *data, size_t size)
> +static int ucsi_send_command_common(struct ucsi *ucsi, u64 command,
> + void *data, size_t size, bool conn_ack)
> {
> u8 length;
> int ret;
> @@ -192,7 +186,7 @@ int ucsi_send_command(struct ucsi *ucsi, u64 command,
> goto out;
> }
>
> - ret = ucsi_acknowledge_command(ucsi);
> + ret = ucsi_acknowledge(ucsi, conn_ack);
> if (ret)
> goto out;
>
> @@ -201,6 +195,12 @@ int ucsi_send_command(struct ucsi *ucsi, u64 command,
> mutex_unlock(&ucsi->ppm_lock);
> return ret;
> }
> +
> +int ucsi_send_command(struct ucsi *ucsi, u64 command,
> + void *data, size_t size)
> +{
> + return ucsi_send_command_common(ucsi, command, data, size, false);
> +}
> EXPORT_SYMBOL_GPL(ucsi_send_command);
>
> /* -------------------------------------------------------------------------- */
> @@ -1168,7 +1168,9 @@ static void ucsi_handle_connector_change(struct work_struct *work)
> mutex_lock(&con->lock);
>
> command = UCSI_GET_CONNECTOR_STATUS | UCSI_CONNECTOR_NUMBER(con->num);
> - ret = ucsi_send_command(ucsi, command, &con->status, sizeof(con->status));
> +
> + ret = ucsi_send_command_common(ucsi, command, &con->status,
> + sizeof(con->status), true);
> if (ret < 0) {
> dev_err(ucsi->dev, "%s: GET_CONNECTOR_STATUS failed (%d)\n",
> __func__, ret);
> @@ -1225,14 +1227,6 @@ static void ucsi_handle_connector_change(struct work_struct *work)
> if (con->status.change & UCSI_CONSTAT_CAM_CHANGE)
> ucsi_partner_task(con, ucsi_check_altmodes, 1, 0);
>
> - mutex_lock(&ucsi->ppm_lock);
> - clear_bit(EVENT_PENDING, &con->ucsi->flags);
> - ret = ucsi_acknowledge_connector_change(ucsi);
> - mutex_unlock(&ucsi->ppm_lock);
> -
> - if (ret)
> - dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret);
> -
> out_unlock:
> mutex_unlock(&con->lock);
> }
> --
> 2.40.1
--
heikki
