From: Hans de Goede <hdegoede@xxxxxxxxxx> commit 25794e3079d2a98547b6bf5764ef0240aa89b798 upstream. The ppm_lock really only needs to be hold during 2 functions: ucsi_reset_ppm() and ucsi_run_command(). Push the taking of the lock down into these 2 functions, renaming ucsi_run_command() to ucsi_send_command() which was an existing wrapper already taking the lock for its callers. This simplifies things for the callers and removes the difference between ucsi_send_command() and ucsi_run_command() which has led to various locking bugs in the past. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200809141904.4317-4-hdegoede@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/typec/ucsi/ucsi.c | 56 ++++++++++++++++-------------------------- 1 file changed, 22 insertions(+), 34 deletions(-) --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -146,42 +146,33 @@ static int ucsi_exec_command(struct ucsi return UCSI_CCI_LENGTH(cci); } -static int ucsi_run_command(struct ucsi *ucsi, u64 command, - void *data, size_t size) +int ucsi_send_command(struct ucsi *ucsi, u64 command, + void *data, size_t size) { u8 length; int ret; - WARN_ON(!mutex_is_locked(&ucsi->ppm_lock)); + mutex_lock(&ucsi->ppm_lock); ret = ucsi_exec_command(ucsi, command); if (ret < 0) - return ret; + goto out; length = ret; if (data) { ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, data, size); if (ret) - return ret; + goto out; } ret = ucsi_acknowledge_command(ucsi); if (ret) - return ret; - - return length; -} + goto out; -int ucsi_send_command(struct ucsi *ucsi, u64 command, - void *retval, size_t size) -{ - int ret; - - mutex_lock(&ucsi->ppm_lock); - ret = ucsi_run_command(ucsi, command, retval, size); + ret = length; +out: mutex_unlock(&ucsi->ppm_lock); - return ret; } EXPORT_SYMBOL_GPL(ucsi_send_command); @@ -738,20 +729,24 @@ static int ucsi_reset_ppm(struct ucsi *u u32 cci; int ret; + mutex_lock(&ucsi->ppm_lock); + ret = ucsi->ops->async_write(ucsi, UCSI_CONTROL, &command, sizeof(command)); if (ret < 0) - return ret; + goto out; tmo = jiffies + msecs_to_jiffies(UCSI_TIMEOUT_MS); do { - if (time_is_before_jiffies(tmo)) - return -ETIMEDOUT; + if (time_is_before_jiffies(tmo)) { + ret = -ETIMEDOUT; + goto out; + } ret = ucsi->ops->read(ucsi, UCSI_CCI, &cci, sizeof(cci)); if (ret) - return ret; + goto out; /* If the PPM is still doing something else, reset it again. */ if (cci & ~UCSI_CCI_RESET_COMPLETE) { @@ -759,13 +754,15 @@ static int ucsi_reset_ppm(struct ucsi *u &command, sizeof(command)); if (ret < 0) - return ret; + goto out; } msleep(20); } while (!(cci & UCSI_CCI_RESET_COMPLETE)); - return 0; +out: + mutex_unlock(&ucsi->ppm_lock); + return ret; } static int ucsi_role_cmd(struct ucsi_connector *con, u64 command) @@ -777,9 +774,7 @@ static int ucsi_role_cmd(struct ucsi_con u64 c; /* PPM most likely stopped responding. Resetting everything. */ - mutex_lock(&con->ucsi->ppm_lock); ucsi_reset_ppm(con->ucsi); - mutex_unlock(&con->ucsi->ppm_lock); c = UCSI_SET_NOTIFICATION_ENABLE | con->ucsi->ntfy; ucsi_send_command(con->ucsi, c, NULL, 0); @@ -1010,8 +1005,6 @@ int ucsi_init(struct ucsi *ucsi) int ret; int i; - mutex_lock(&ucsi->ppm_lock); - /* Reset the PPM */ ret = ucsi_reset_ppm(ucsi); if (ret) { @@ -1022,13 +1015,13 @@ int ucsi_init(struct ucsi *ucsi) /* Enable basic notifications */ ucsi->ntfy = UCSI_ENABLE_NTFY_CMD_COMPLETE | UCSI_ENABLE_NTFY_ERROR; command = UCSI_SET_NOTIFICATION_ENABLE | ucsi->ntfy; - ret = ucsi_run_command(ucsi, command, NULL, 0); + ret = ucsi_send_command(ucsi, command, NULL, 0); if (ret < 0) goto err_reset; /* Get PPM capabilities */ command = UCSI_GET_CAPABILITY; - ret = ucsi_run_command(ucsi, command, &ucsi->cap, sizeof(ucsi->cap)); + ret = ucsi_send_command(ucsi, command, &ucsi->cap, sizeof(ucsi->cap)); if (ret < 0) goto err_reset; @@ -1045,8 +1038,6 @@ int ucsi_init(struct ucsi *ucsi) goto err_reset; } - mutex_unlock(&ucsi->ppm_lock); - /* Register all connectors */ for (i = 0; i < ucsi->cap.num_connectors; i++) { ret = ucsi_register_port(ucsi, i); @@ -1072,12 +1063,9 @@ err_unregister: con->port = NULL; } - mutex_lock(&ucsi->ppm_lock); err_reset: ucsi_reset_ppm(ucsi); err: - mutex_unlock(&ucsi->ppm_lock); - return ret; } EXPORT_SYMBOL_GPL(ucsi_init);
