Commit de52aca4 authored by Christian A. Ehrhardt's avatar Christian A. Ehrhardt Committed by Greg Kroah-Hartman
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usb: typec: ucsi: Never send a lone connector change ack 



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: default avatarChristian A. Ehrhardt <lk@c--e.de>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20240327224554.1772525-3-lk@c--e.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f3031f9b

drivers/usb/typec/ucsi/ucsi.c

+21 −27
Original line number Diff line number Diff line
@@ -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;

	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);



/* -------------------------------------------------------------------------- */
@@ -1187,7 +1187,9 @@ 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);
@@ -1244,14 +1246,6 @@ 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);

}