On Tue, Mar 29, 2016 at 04:46:30PM -0400, Lyude wrote: > On Valleyview, VGA hotplugging is controlled through a seperate register > than everything else, VLV_ADPA, which must be explicitly set. > > While VGA hotplugging worked(ish) before, it looks like that was mainly > because we'd unintentionally enable it in > valleyview_crt_detect_hotplug() when we did a force trigger. This > doesn't work reliably enough because whenever the display powerwell on > vlv gets disabled, the values set in VLV_ADPA get cleared and > consequently VGA hotplugging gets disabled. This causes bugs such as one > we found on an Intel NUC, where doing the following sequence of > hotplugs: > > - Disconnect all monitors > - Connect VGA > - Disconnect VGA > - Connect HDMI > > Would result in hotplugging getting disabled, due to the display > powerwells getting toggled in the process of connecting HDMI. > > CC: stable@xxxxxxxxxxxxxxx > Signed-off-by: Lyude <cpaul@xxxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_irq.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c > index 5aa4239..60592a4 100644 > --- a/drivers/gpu/drm/i915/i915_irq.c > +++ b/drivers/gpu/drm/i915/i915_irq.c > @@ -3611,6 +3611,7 @@ static void valleyview_display_irqs_install(struct drm_i915_private *dev_priv) > { > u32 pipestat_mask; > u32 iir_mask; > + u32 adpa_reg; > enum pipe pipe; > > pipestat_mask = PIPESTAT_INT_STATUS_MASK | > @@ -3627,6 +3628,12 @@ static void valleyview_display_irqs_install(struct drm_i915_private *dev_priv) > for_each_pipe(dev_priv, pipe) > i915_enable_pipestat(dev_priv, pipe, pipestat_mask); > > + if (IS_VALLEYVIEW(dev_priv)) { > + adpa_reg = I915_READ(VLV_ADPA); > + adpa_reg |= ADPA_CRT_HOTPLUG_ENABLE; > + I915_WRITE(VLV_ADPA, adpa_reg); > + } We might not want to enable that when there's no VGA connector. Seems like we should just be calling intel_crt_reset() here. We definitely don't want to call the reset for hooks for all the other connectors so drm_mode_config_reset() is out. Also the connector locking might be problematic here, so I might suggest adjusting intel_crt_reset() to take an encoder instead of connector, and then we should be able to walk the encoder list without any troubles. > + > iir_mask = I915_DISPLAY_PORT_INTERRUPT | > I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | > I915_DISPLAY_PIPE_B_EVENT_INTERRUPT; > @@ -3645,8 +3652,15 @@ static void valleyview_display_irqs_uninstall(struct drm_i915_private *dev_priv) > { > u32 pipestat_mask; > u32 iir_mask; > + u32 adpa_reg; > enum pipe pipe; > > + if (IS_VALLEYVIEW(dev_priv)) { > + adpa_reg = I915_READ(VLV_ADPA); > + adpa_reg &= ~ADPA_CRT_HOTPLUG_ENABLE; > + I915_WRITE(VLV_ADPA, adpa_reg); > + } > + > iir_mask = I915_DISPLAY_PORT_INTERRUPT | > I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | > I915_DISPLAY_PIPE_B_EVENT_INTERRUPT; > -- > 2.5.5 > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Ville Syrjälä Intel OTC -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html