thermal: intel: int340x: processor_thermal: Fix deadlock

BugLink: https://bugs.launchpad.net/bugs/2016875
commit 52f04f10b9005ac4ce640da14a52ed7a146432fa upstream.

When user space updates the trip point there is a deadlock, which results
in caller gets blocked forever.

Commit 05eeee2b51b4 ("thermal/core: Protect sysfs accesses to thermal
operations with thermal zone mutex"), added a mutex for tz->lock in the
function trip_point_temp_store(). Hence, trip set callback() can't
call any thermal zone API as they are protected with the same mutex lock.

The callback here calling thermal_zone_device_enable(), which will result
in deadlock.

Move the thermal_zone_device_enable() to proc_thermal_pci_probe() to
avoid this deadlock.

Fixes: 05eeee2b51b4 ("thermal/core: Protect sysfs accesses to thermal operations with thermal zone mutex")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
Cc: 6.2+ <stable@vger.kernel.org> # 6.2+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
index bf1b1cdfade4a27d691e7c20e36beb0373e721ee..acc11ad569758c8d75c88a416610f9063de08ff1 100644 (file)
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
@@ -194,7 +194,6 @@ static int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp
        proc_thermal_mmio_write(pci_info, PROC_THERMAL_MMIO_THRES_0, _temp);
        proc_thermal_mmio_write(pci_info, PROC_THERMAL_MMIO_INT_ENABLE_0, 1);
 
-       thermal_zone_device_enable(tzd);
        pci_info->stored_thres = temp;
 
        return 0;
@@ -277,6 +276,10 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, const struct pci_device_
                goto err_free_vectors;
        }
 
+       ret = thermal_zone_device_enable(pci_info->tzone);
+       if (ret)
+               goto err_free_vectors;
+
        return 0;
 
 err_free_vectors: