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usb: typec: ucsi: Rework ppm_lock handling 

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@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200809141904.4317-4-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hans de Goede 2020-08-09 16:19:03 +02:00 committed by Greg Kroah-Hartman
parent 7e90057f12
commit 25794e3079
1 changed files with 22 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
drivers/usb/typec/ucsi/ucsi.c
View File

@ -146,42 +146,33 @@ static int ucsi_exec_command(struct ucsi *ucsi, u64 cmd)
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;
goto out;
return length;
}
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 *ucsi)
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 *ucsi)
&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_connector *con, u64 command)
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 @@ static 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 @@ static 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 @@ static 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;
}