On Mon, 22 Aug 2022, Imre Deak <imre.deak@xxxxxxxxx> wrote: > 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.hajda@xxxxxxxxx> >> Reviewed-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx> >> --- >> 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(). The high level i915_driver_remove() code should only call high level display functions, not something like intel_dp_mst_suspend() directly. BR, Jani. > >> /* 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 >> -- Jani Nikula, Intel Open Source Graphics Center
