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path: root/drivers/gpu/drm/i915/intel_crt.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_crt.c')
-rw-r--r--drivers/gpu/drm/i915/intel_crt.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index d172930ac1e7..827b6ef4e9ae 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -329,10 +329,25 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector)
struct drm_device *dev = connector->dev;
struct intel_crt *crt = intel_attached_crt(connector);
struct drm_i915_private *dev_priv = to_i915(dev);
+ bool reenable_hpd;
u32 adpa;
bool ret;
u32 save_adpa;
+ /*
+ * Doing a force trigger causes a hpd interrupt to get sent, which can
+ * get us stuck in a loop if we're polling:
+ * - We enable power wells and reset the ADPA
+ * - output_poll_exec does force probe on VGA, triggering a hpd
+ * - HPD handler waits for poll to unlock dev->mode_config.mutex
+ * - output_poll_exec shuts off the ADPA, unlocks
+ * dev->mode_config.mutex
+ * - HPD handler runs, resets ADPA and brings us back to the start
+ *
+ * Just disable HPD interrupts here to prevent this
+ */
+ reenable_hpd = intel_hpd_disable(dev_priv, crt->base.hpd_pin);
+
save_adpa = adpa = I915_READ(crt->adpa_reg);
DRM_DEBUG_KMS("trigger hotplug detect cycle: adpa=0x%x\n", adpa);
@@ -357,6 +372,9 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector)
DRM_DEBUG_KMS("valleyview hotplug adpa=0x%x, result %d\n", adpa, ret);
+ if (reenable_hpd)
+ intel_hpd_enable(dev_priv, crt->base.hpd_pin);
+
return ret;
}
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