diff options
author | Bryan O'Donoghue <bryan.odonoghue@linaro.org> | 2016-06-23 16:26:00 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@google.com> | 2016-06-23 14:15:21 -0700 |
commit | 1211915127c152a86e68ea35770c9e2524020d4f (patch) | |
tree | 792c2797e1a18c28e7ca2598dfba2acc2ea28662 /drivers/staging/greybus/interface.c | |
parent | 5e2b63915cb6f1e86f9515342cfcfb28cd82c5b0 (diff) |
greybus: timesync: Enforce TimeSync locks as subordinate to Interface locks
gb_timesync_svc_teardown() is called from gb_timesync_svc_del() and issues a
command to a remote Interface to switch off its timers. The lock ordering
is TimeSync => Interface in this case. However gb_module_del() takes an
Interface lock then calls gb_interface_del() => gb_timesync_svc_del() in
this case the lock ordering is Interface => TimeSync.
This patch fixes by removing the taking of the Interface mutex in
gb_interface_timesync_do_something(). If an Interface is present in the
TimeSync linked-list - it is by definition intf->enabled.
Reported-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Diffstat (limited to 'drivers/staging/greybus/interface.c')
-rw-r--r-- | drivers/staging/greybus/interface.c | 50 |
1 files changed, 9 insertions, 41 deletions
diff --git a/drivers/staging/greybus/interface.c b/drivers/staging/greybus/interface.c index 9b90209e8fe0..05d0020d3a8d 100644 --- a/drivers/staging/greybus/interface.c +++ b/drivers/staging/greybus/interface.c @@ -872,59 +872,27 @@ void gb_interface_disable(struct gb_interface *intf) intf->enabled = false; } -/* - * Enable TimeSync on an Interface control connection. - * - * Locking: Takes and releases the interface mutex. - */ +/* Enable TimeSync on an Interface control connection. */ int gb_interface_timesync_enable(struct gb_interface *intf, u8 count, u64 frame_time, u32 strobe_delay, u32 refclk) { - int ret = -ENODEV; - - mutex_lock(&intf->mutex); - if (intf->enabled) { - ret = gb_control_timesync_enable(intf->control, count, - frame_time, strobe_delay, - refclk); - } - mutex_unlock(&intf->mutex); - return ret; + return gb_control_timesync_enable(intf->control, count, + frame_time, strobe_delay, + refclk); } -/* - * Disable TimeSync on an Interface control connection. - * - * Locking: Takes and releases the interface mutex. - */ +/* Disable TimeSync on an Interface control connection. */ int gb_interface_timesync_disable(struct gb_interface *intf) { - int ret = -ENODEV; - - mutex_lock(&intf->mutex); - if (intf->enabled) - ret = gb_control_timesync_disable(intf->control); - mutex_unlock(&intf->mutex); - return ret; + return gb_control_timesync_disable(intf->control); } -/* - * Transmit the Authoritative FrameTime via an Interface control connection. - * - * Locking: Takes and releases the interface mutex. - */ +/* Transmit the Authoritative FrameTime via an Interface control connection. */ int gb_interface_timesync_authoritative(struct gb_interface *intf, u64 *frame_time) { - int ret = -ENODEV; - - mutex_lock(&intf->mutex); - if (intf->enabled) { - ret = gb_control_timesync_authoritative(intf->control, - frame_time); - } - mutex_unlock(&intf->mutex); - return ret; + return gb_control_timesync_authoritative(intf->control, + frame_time); } /* Register an interface. */ |