hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

mei: amthif: fix deadlock in initialization during a reset 

The device lock was unnecessary obtained in bus rescan work before the
amthif client search.  That causes incorrect lock ordering and task
hang:
...
[88004.613213] INFO: task kworker/1:14:21832 blocked for more than 120 seconds.
...
[88004.645934] Workqueue: events mei_cl_bus_rescan_work
...

The correct lock order is
 cl_bus_lock
  device_lock
   me_clients_rwsem

Move device_lock into amthif init function that called
after me_clients_rwsem is released.

This fixes regression introduced by commit:
commit 025fb792ba ("mei: split amthif client init from end of clients enumeration")

Cc: <stable@vger.kernel.org> # 4.6+
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexander Usyskin 2016-07-26 01:06:09 +03:00 committed by Greg Kroah-Hartman
parent 80293c47a6
commit e728ae271f
2 changed files with 9 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/misc/mei/amthif.c
View File

@ -66,8 +66,12 @@ int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
struct mei_cl *cl = &dev->iamthif_cl;
int ret;
if (mei_cl_is_connected(cl))
return 0;
mutex_lock(&dev->device_lock);
if (mei_cl_is_connected(cl)) {
ret = 0;
goto out;
}
dev->iamthif_state = MEI_IAMTHIF_IDLE;
@ -76,11 +80,13 @@ int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
ret = mei_cl_link(cl);
if (ret < 0) {
dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
return ret;
goto out;
}
ret = mei_cl_connect(cl, me_cl, NULL);
out:
mutex_unlock(&dev->device_lock);
return ret;
}

2
drivers/misc/mei/bus.c
View File

@ -984,12 +984,10 @@ void mei_cl_bus_rescan_work(struct work_struct *work)
container_of(work, struct mei_device, bus_rescan_work);
struct mei_me_client *me_cl;
mutex_lock(&bus->device_lock);
me_cl = mei_me_cl_by_uuid(bus, &mei_amthif_guid);
if (me_cl)
mei_amthif_host_init(bus, me_cl);
mei_me_cl_put(me_cl);
mutex_unlock(&bus->device_lock);
mei_cl_bus_rescan(bus);
}