drm/i915/display: convert inner wakeref get towards get_if_in_use

This patch brings no functional change. Since at this point of
the code we are already asserting a wakeref was held, it means
that we are with runtime_pm 'in_use' and in practical terms we
are only bumping the pm_runtime usage counter and moving on.

However, xe driver has a lockdep annotation that warned us that
if a sync resume was actually called at this point, we could have
a deadlock because we are inside the power_domains->lock locked
area and the resume would call the irq_reset, which would also
try to get the power_domains->lock.

For this reason, let's convert this call to a safer option and
calm lockdep on.

v2: use _noresume variant instead of get_in_use (Ville, Imre)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Imre Deak <imre.deak@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240417203952.25503-3-rodrigo.vivi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index 6fd4fa52253a35a02957509d7135310346242d41..048943d0a881c9cb647e73ef1ead0597d1138ed2 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -646,7 +646,7 @@ release_async_put_domains(struct i915_power_domains *power_domains,
         * power well disabling.
         */
        assert_rpm_raw_wakeref_held(rpm);
-       wakeref = intel_runtime_pm_get(rpm);
+       wakeref = intel_runtime_pm_get_noresume(rpm);
 
        for_each_power_domain(domain, mask) {
                /* Clear before put, so put's sanity check is happy. */