Commit 882244a3 authored Apr 01, 2014 by Paulo Zanoni Committed by Daniel Vetter Apr 01, 2014

drm/i915: fix WARNs when reading DDI state while suspended



If runtime PM is enabled and we unset all modes, we will runtime
suspend after __intel_set_mode() , then function
intel_modeset_check_state() will try to read the HW state while it is
suspended and trigger lots of WARNs because it shouldn't be reading
registers.

So on this patch we make intel_ddi_connector_get_hw_state() return
false in case the power domain is disabled, and we also make
intel_display_power_enabled() return false in case the device is
suspended. Notice that we can't just use
intel_display_power_enabled_sw() because while the driver is being
initialized the power domain refcounts are not reflecting the real
state of the hardware.

Just for reference, I have previously published an alternate patch for
this problem, called "drm/i915: get runtime PM at intel_set_mode".

Testcase: igt/pm_pc8
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

parent a23dc658

drivers/gpu/drm/i915/intel_ddi.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1108,8 +1108,13 @@ bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
		enum port port = intel_ddi_get_encoder_port(intel_encoder);
		enum pipe pipe = 0;
		enum transcoder cpu_transcoder;
		enum intel_display_power_domain power_domain;
		uint32_t tmp;

		power_domain = intel_display_port_power_domain(intel_encoder);
		if (!intel_display_power_enabled(dev_priv, power_domain))
		return false;

		if (!intel_encoder->get_hw_state(intel_encoder, &pipe))
		return false;

drivers/gpu/drm/i915/intel_pm.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -5280,6 +5280,9 @@ bool intel_display_power_enabled(struct drm_i915_private *dev_priv,
		bool is_enabled;
		int i;

		if (dev_priv->pm.suspended)
		return false;

		power_domains = &dev_priv->power_domains;

		is_enabled = true;