On Fri, Jul 22, 2022 at 02:51:40PM +0200, Andrzej Hajda wrote: > i915->hotplug.dig_port_work can be queued from intel_hpd_irq_handler > called by IRQ handler or by intel_hpd_trigger_irq called from dp_mst. > Since dp_mst is suspended after irq handler uninstall, a cleaner approach > is to cancel hpd work after intel_dp_mst_suspend, otherwise we risk > use-after-free. > > It should fix following WARNINGS: > [283.405824] cpu_latency_qos_update_request called for unknown object > [283.405866] WARNING: CPU: 2 PID: 240 at kernel/power/qos.c:296 > cpu_latency_qos_update_request+0x2d/0x100 > [283.405912] CPU: 2 PID: 240 Comm: kworker/u64:9 Not tainted > 5.18.0-rc6-Patchwork_103738v3-g1672d1c43e43+ #1 > [283.405915] Hardware name: Intel Corporation Raptor Lake Client > Platform/RPL-S ADP-S DDR5 UDIMM CRB, BIOS RPLSFWI1.R00.2397.A01.2109300731 > 09/30/2021 > [283.405916] Workqueue: i915-dp i915_digport_work_func [i915] > [283.406020] RIP: 0010:cpu_latency_qos_update_request+0x2d/0x100 > ... > [283.406040] Call Trace: > [283.406041] <TASK> > [283.406044] intel_dp_aux_xfer+0x60e/0x8e0 [i915] > [283.406131] ? finish_swait+0x80/0x80 > [283.406139] intel_dp_aux_transfer+0xc5/0x2b0 [i915] > [283.406218] drm_dp_dpcd_access+0x79/0x130 [drm_display_helper] > [283.406227] drm_dp_dpcd_read+0xe2/0xf0 [drm_display_helper] > [283.406233] intel_dp_hpd_pulse+0x134/0x570 [i915] > [283.406308] ? __down_killable+0x70/0x140 > [283.406313] i915_digport_work_func+0xba/0x150 [i915] > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4586 > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5558 > Signed-off-by: Andrzej Hajda <andrzej.ha...@intel.com> > Reviewed-by: Arun R Murthy <arun.r.mur...@intel.com> > --- > drivers/gpu/drm/i915/display/intel_display.c | 3 +++ > drivers/gpu/drm/i915/i915_irq.c | 1 - > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c > b/drivers/gpu/drm/i915/display/intel_display.c > index a0f84cbe974fc3..f1c765ac7ab8aa 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -9021,6 +9021,9 @@ void intel_modeset_driver_remove_noirq(struct > drm_i915_private *i915) > */ > intel_dp_mst_suspend(i915); > > + /* MST is the last user of HPD work */ > + intel_hpd_cancel_work(i915); > +
MST still requires AUX and short HPD interrupts and during shutdown and suspend the order is suspend-MST -> disable-IRQs. So I think it makes more sense to move intel_dp_mst_suspend() to i915_driver_remove() before intel_irq_uninstall(). > /* poll work can call into fbdev, hence clean that up afterwards */ > intel_fbdev_fini(i915); > > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c > index 73cebc6aa65072..db14787aef95dd 100644 > --- a/drivers/gpu/drm/i915/i915_irq.c > +++ b/drivers/gpu/drm/i915/i915_irq.c > @@ -4597,7 +4597,6 @@ void intel_irq_uninstall(struct drm_i915_private > *dev_priv) > > free_irq(irq, dev_priv); > > - intel_hpd_cancel_work(dev_priv); > dev_priv->runtime_pm.irqs_enabled = false; > } > > -- > 2.25.1 >
