drm/i915: Use tasklet_unlock_spin_wait() in __tasklet_disable_sync_once()

The i915 driver has its own tasklet interface which was overseen in the
tasklet rework. __tasklet_disable_sync_once() is a wrapper around
tasklet_unlock_wait(). tasklet_unlock_wait() might sleep, but the i915
wrappers invokes it from non-preemtible contexts with bottom halves disabled.

Use tasklet_unlock_spin_wait() instead which can be invoked from
non-preemptible contexts.

Fixes: da044747401fc ("tasklets: Replace spin wait in tasklet_unlock_wait()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210323092221.awq7g5b2muzypjw3@flow

diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h
index e622aee..440c35f 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.h
+++ b/drivers/gpu/drm/i915/i915_gem.h
@@ -105,7 +105,7 @@ static inline bool tasklet_is_locked(const struct tasklet_struct *t)
 static inline void __tasklet_disable_sync_once(struct tasklet_struct *t)
 {
        if (!atomic_fetch_inc(&t->count))
-               tasklet_unlock_wait(t);
+               tasklet_unlock_spin_wait(t);
 }
 
 static inline bool __tasklet_is_enabled(const struct tasklet_struct *t)