i915: TV hotplug fixes

In order to avoid recursive ->detect->interrupt->detect->interrupt->...
we need to disable TV hotplug interrupts in
intel_tv.c:intel_tv_detect_type.  We also need to enable the TV interrupt
detection and hotplug sequence properly in i915_irq.c.

2 files changed, 36 insertions, 8 deletions

diff --git a/linux-core/intel_tv.c b/linux-core/intel_tv.c
index ba134d62..865e27b9 100644
--- a/linux-core/intel_tv.c
+++ b/linux-core/intel_tv.c
@@ -1360,11 +1360,21 @@ intel_tv_detect_type (struct drm_crtc *crtc, struct drm_output *output)
 	struct drm_device *dev = output->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_output *intel_output = output->driver_private;
+	u32 pipeastat, pipeastat_save;
 	u32 tv_ctl, save_tv_ctl;
 	u32 tv_dac, save_tv_dac;
 	int type = ConnectorUnknown;
 
 	tv_dac = I915_READ(TV_DAC);
+
+	/* Disable TV interrupts around load detect or we'll recurse */
+	pipeastat = I915_READ(I915REG_PIPEASTAT);
+	pipeastat_save = pipeastat;
+	pipeastat &= ~I915_HOTPLUG_INTERRUPT_ENABLE;
+	pipeastat &= ~I915_HOTPLUG_TV_INTERRUPT_ENABLE;
+	I915_WRITE(I915REG_PIPEASTAT, pipeastat | I915_HOTPLUG_TV_CLEAR |
+		   I915_HOTPLUG_CLEAR);
+
 	/*
 	 * Detect TV by polling)
 	 */
@@ -1412,6 +1422,10 @@ intel_tv_detect_type (struct drm_crtc *crtc, struct drm_output *output)
 		type = -1;
 	}
 
+	/* Restore interrupt config */
+	I915_WRITE(I915REG_PIPEASTAT, pipeastat_save | I915_HOTPLUG_TV_CLEAR |
+		   I915_HOTPLUG_CLEAR);
+
 	return type;
 }
 
@@ -1434,10 +1448,15 @@ intel_tv_detect(struct drm_output *output)
 	mode = reported_modes[0];
 	drm_mode_set_crtcinfo(&mode, CRTC_INTERLACE_HALVE_V);
 
-	crtc = intel_get_load_detect_pipe(output, &mode, &dpms_mode);
-	if (crtc) {
-		type = intel_tv_detect_type(crtc, output);
-		intel_release_load_detect_pipe(output, dpms_mode);
+	if (output->crtc) {
+		type = intel_tv_detect_type(output->crtc, output);
+	} else {
+		crtc = intel_get_load_detect_pipe(output, &mode, &dpms_mode);
+		if (crtc) {
+			type = intel_tv_detect_type(crtc, output);
+			intel_release_load_detect_pipe(output, dpms_mode);
+		} else
+			type = -1;
 	}
 
 	if (type != tv_priv->type) {
diff --git a/shared-core/i915_irq.c b/shared-core/i915_irq.c
index 0ee0c444..4aef568e 100644
--- a/shared-core/i915_irq.c
+++ b/shared-core/i915_irq.c
@@ -471,7 +471,6 @@ static void i915_hotplug_tv(struct drm_device *dev)
 	if (iout == 0)
 		goto unlock;
 
-	/* may need to I915_WRITE(TVDAC, 1<<31) to ack the interrupt */
 	status = output->funcs->detect(output);
 	drm_hotplug_stage_two(dev, output,
 			      status == output_status_connected ? 1 : 0);
@@ -631,7 +630,7 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 	struct drm_i915_master_private *master_priv;
 	struct drm_i915_private *dev_priv = (struct drm_i915_private *) dev->dev_private;
 	u32 iir;
-	u32 pipea_stats, pipeb_stats;
+	u32 pipea_stats = 0, pipeb_stats, tvdac;
 	int hotplug = 0;
 	int vblank = 0;
 
@@ -672,10 +671,17 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 		}
 
 		/* This is a global event, and not a pipe A event */
-		if ((pipea_stats & I915_HOTPLUG_INTERRUPT_STATUS) ||
-		    (pipea_stats & I915_HOTPLUG_TV_INTERRUPT_STATUS))
+		if (pipea_stats & I915_HOTPLUG_INTERRUPT_STATUS)
 			hotplug = 1;
 
+		if (pipea_stats & I915_HOTPLUG_TV_INTERRUPT_STATUS) {
+			hotplug = 1;
+			/* Toggle hotplug detection to clear hotplug status */
+			tvdac = I915_READ(TV_DAC);
+			I915_WRITE(TV_DAC, tvdac & ~TVDAC_STATE_CHG_EN);
+			I915_WRITE(TV_DAC, tvdac | TVDAC_STATE_CHG_EN);
+		}
+
 		I915_WRITE(I915REG_PIPEASTAT, pipea_stats);
 	}
 
@@ -1001,6 +1007,9 @@ void i915_enable_interrupt (struct drm_device *dev)
 
 			I915_WRITE(SDVOB, I915_READ(SDVOB) | SDVO_INTERRUPT_ENABLE);
 			I915_WRITE(SDVOC, I915_READ(SDVOC) | SDVO_INTERRUPT_ENABLE);
+
+			/* TV */
+			I915_WRITE(TV_DAC, I915_READ(TV_DAC) | TVDAC_STATE_CHG_EN);
 		} else {
 			/* DVO ???? */
 		}