thermal: Fix potential deadlock in cpu_cooling

cooling_list_lock is covering not just cpufreq_dev_count, but also the
calls to cpufreq_register_notifier() and cpufreq_unregister_notifier().

Since cooling_list_lock is also used within cpufreq_thermal_notifier(),
lockdep reports a potential deadlock. Fix it by testing the condition
under cooling_list_lock and dropping the lock before calling
cpufreq_register_notifier(). And variable cpufreq_dev_count is removed
at the same time, because it's no longer needed after the fix.

Fixes: ae606089621e ("thermal: convert cpu_cooling to use an IDA")
Reported-and-Tested-by: Russell King <[email protected]>
Signed-off-by: Matthew Wilcox <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]
Signed-off-by: Zhang Rui <[email protected]>

0 files changed, 0 insertions, 0 deletions