On Fri, Jan 05, 2024 at 02:54:06PM +0200, Hogander, Jouni wrote: > On Thu, 2024-01-04 at 10:29 +0200, Imre Deak wrote: > > After an HPD IRQ storm on a connector intel_hpd_irq_storm_detect() > > will > > set the connector's HPD pin state to HPD_MARK_DISABLED and the IRQ > > gets > > disabled. Subsequently intel_hpd_irq_storm_switch_to_polling() will > > enable polling for these connectors, setting the pin state to > > HPD_DISABLED, but only if the connector's base.polled field is set to > > DRM_CONNECTOR_POLL_HPD. intel_hpd_irq_storm_reenable_work() will > > reenable the IRQ - after 2 minutes - if the pin state is > > HPD_DISABLED. > > > > The connectors will be created with their base.polled field set to 0, > > which gets initialized only later in i915_hpd_poll_init_work() (using > > intel_connector::polled). If a storm is detected on a connector after > > it's created and IRQs are enabled on it - by intel_hpd_init() - and > > before its bease.polled field is initialized in the above work, the > > connector's HPD pin will stay in the HPD_MARK_DISABLED state - > > leaving > > the IRQ disabled indefinitely - and polling will not get enabled on > > it as > > intended. > > > > I can't see a reason for initializing base.polled in a delayed > > manner, > > so do this already when creating the connector, to prevent the above > > race condition. > > To me it looks like intel_connector::polled is used just to store > original drm_connector::polled value and restore it in > intel_hpd_irq_storm_reenable_work: > > if (connector->base.polled != connector->polled) > drm_dbg(&dev_priv->drm, > "Reenabling HPD on connector %s\n", > connector->base.name); > connector->base.polled = connector->polled; Correct and restored similarly in i915_hpd_poll_init_work(). Originaly intel_connector::polled was added to avoid misconfiguring a connector's polled state in these two places if the two connectors share an HPD pin (one of them needing polling the other one using the HPD pin; not sure the exact scenario where this is actually possible). But I can't see why at this moment we couldn't initialize the original base.polled value early. > From this perspective it is right thing to do to initialize connector- > base.polled as you are doing in this patch. > > Reviewed-by: Jouni Högander <jouni.hogander@xxxxxxxxx> > > > > > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/display/intel_crt.c | 1 + > > drivers/gpu/drm/i915/display/intel_dp.c | 1 + > > drivers/gpu/drm/i915/display/intel_dvo.c | 1 + > > drivers/gpu/drm/i915/display/intel_hdmi.c | 1 + > > drivers/gpu/drm/i915/display/intel_sdvo.c | 2 ++ > > drivers/gpu/drm/i915/display/intel_tv.c | 1 + > > 6 files changed, 7 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_crt.c > > b/drivers/gpu/drm/i915/display/intel_crt.c > > index abaacea5c2cc4..b330337b842a4 100644 > > --- a/drivers/gpu/drm/i915/display/intel_crt.c > > +++ b/drivers/gpu/drm/i915/display/intel_crt.c > > @@ -1069,6 +1069,7 @@ void intel_crt_init(struct drm_i915_private > > *dev_priv) > > } else { > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT; > > } > > + intel_connector->base.polled = intel_connector->polled; > > > > if (HAS_DDI(dev_priv)) { > > assert_port_valid(dev_priv, PORT_E); > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c > > b/drivers/gpu/drm/i915/display/intel_dp.c > > index 9ff0cbd9c0df5..fed649af8fc85 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > @@ -6469,6 +6469,7 @@ intel_dp_init_connector(struct > > intel_digital_port *dig_port, > > connector->interlace_allowed = true; > > > > intel_connector->polled = DRM_CONNECTOR_POLL_HPD; > > + intel_connector->base.polled = intel_connector->polled; > > > > intel_connector_attach_encoder(intel_connector, > > intel_encoder); > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dvo.c > > b/drivers/gpu/drm/i915/display/intel_dvo.c > > index 9111e9d46486d..83898ba493d16 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dvo.c > > +++ b/drivers/gpu/drm/i915/display/intel_dvo.c > > @@ -536,6 +536,7 @@ void intel_dvo_init(struct drm_i915_private > > *i915) > > if (intel_dvo->dev.type == INTEL_DVO_CHIP_TMDS) > > connector->polled = DRM_CONNECTOR_POLL_CONNECT | > > DRM_CONNECTOR_POLL_DISCONNECT; > > + connector->base.polled = connector->polled; > > > > drm_connector_init_with_ddc(&i915->drm, &connector->base, > > &intel_dvo_connector_funcs, > > diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c > > b/drivers/gpu/drm/i915/display/intel_hdmi.c > > index eedef8121ff7c..55048c56bc527 100644 > > --- a/drivers/gpu/drm/i915/display/intel_hdmi.c > > +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c > > @@ -3017,6 +3017,7 @@ void intel_hdmi_init_connector(struct > > intel_digital_port *dig_port, > > connector->ycbcr_420_allowed = true; > > > > intel_connector->polled = DRM_CONNECTOR_POLL_HPD; > > + intel_connector->base.polled = intel_connector->polled; > > > > if (HAS_DDI(dev_priv)) > > intel_connector->get_hw_state = > > intel_ddi_connector_get_hw_state; > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > index 9218047495fb4..4e4a87f841787 100644 > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > @@ -2805,6 +2805,7 @@ intel_sdvo_dvi_init(struct intel_sdvo > > *intel_sdvo, u16 type) > > } else { > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT > > | DRM_CONNECTOR_POLL_DISCONNECT; > > } > > + intel_connector->base.polled = intel_connector->polled; > > encoder->encoder_type = DRM_MODE_ENCODER_TMDS; > > connector->connector_type = DRM_MODE_CONNECTOR_DVID; > > > > @@ -2880,6 +2881,7 @@ intel_sdvo_analog_init(struct intel_sdvo > > *intel_sdvo, u16 type) > > intel_connector = &intel_sdvo_connector->base; > > connector = &intel_connector->base; > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT; > > + intel_connector->base.polled = intel_connector->polled; > > encoder->encoder_type = DRM_MODE_ENCODER_DAC; > > connector->connector_type = DRM_MODE_CONNECTOR_VGA; > > > > diff --git a/drivers/gpu/drm/i915/display/intel_tv.c > > b/drivers/gpu/drm/i915/display/intel_tv.c > > index d4386cb3569e0..f3598fe39fda5 100644 > > --- a/drivers/gpu/drm/i915/display/intel_tv.c > > +++ b/drivers/gpu/drm/i915/display/intel_tv.c > > @@ -1990,6 +1990,7 @@ intel_tv_init(struct drm_i915_private > > *dev_priv) > > * More recent chipsets favour HDMI rather than integrated S- > > Video. > > */ > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT; > > + intel_connector->base.polled = intel_connector->polled; > > > > drm_connector_init(&dev_priv->drm, connector, > > &intel_tv_connector_funcs, > > DRM_MODE_CONNECTOR_SVIDEO); >