On Tue, 20 Dec 2022, Maarten Lankhorst <[email protected]> wrote: > We enable the DP aux channel during probe, but may free the connector > soon afterwards. Ensure the DP aux display power put is completed before > everything is freed, to prevent a use-after-free in icl_aux_pw_to_phy(), > called from icl_combo_phy_aux_power_well_disable.
Feels like the placement of the intel_display_power_flush_work_sync() call in intel_dp_aux_fini() is a bit arbitrary. If we add it in intel_dp_aux_fini(), the async and sync waits will both be called on the regular encoder destroy path. Maybe both intel_ddi_encoder_destroy() and intel_dp_encoder_destroy() should call intel_display_power_flush_work_sync(), instead of async, and maybe the error paths should call those functions instead of just drm_encoder_cleanup()? Imre? BR, Jani. > > Signed-off-by: Maarten Lankhorst <[email protected]> > --- > drivers/gpu/drm/i915/display/intel_display_power.c | 2 +- > drivers/gpu/drm/i915/display/intel_display_power.h | 1 + > drivers/gpu/drm/i915/display/intel_dp_aux.c | 2 ++ > 3 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c > b/drivers/gpu/drm/i915/display/intel_display_power.c > index 04915f85a0df..0edb5532461f 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_power.c > +++ b/drivers/gpu/drm/i915/display/intel_display_power.c > @@ -776,7 +776,7 @@ void intel_display_power_flush_work(struct > drm_i915_private *i915) > * Like intel_display_power_flush_work(), but also ensure that the work > * handler function is not running any more when this function returns. > */ > -static void > +void > intel_display_power_flush_work_sync(struct drm_i915_private *i915) > { > struct i915_power_domains *power_domains = &i915->display.power.domains; > diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h > b/drivers/gpu/drm/i915/display/intel_display_power.h > index 7136ea3f233e..dc10ee0519e6 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_power.h > +++ b/drivers/gpu/drm/i915/display/intel_display_power.h > @@ -188,6 +188,7 @@ void __intel_display_power_put_async(struct > drm_i915_private *i915, > enum intel_display_power_domain domain, > intel_wakeref_t wakeref); > void intel_display_power_flush_work(struct drm_i915_private *i915); > +void intel_display_power_flush_work_sync(struct drm_i915_private *i915); > #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM) > void intel_display_power_put(struct drm_i915_private *dev_priv, > enum intel_display_power_domain domain, > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c > b/drivers/gpu/drm/i915/display/intel_dp_aux.c > index f1835c74bff0..1006dddad2d5 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c > @@ -680,6 +680,8 @@ void intel_dp_aux_fini(struct intel_dp *intel_dp) > if (cpu_latency_qos_request_active(&intel_dp->pm_qos)) > cpu_latency_qos_remove_request(&intel_dp->pm_qos); > > + /* Ensure async work from intel_dp_aux_xfer() is flushed before we > clean up */ > + intel_display_power_flush_work_sync(dp_to_i915(intel_dp)); > kfree(intel_dp->aux.name); > } -- Jani Nikula, Intel Open Source Graphics Center
