drm/i915: Enable digital port hotplug on PCH systems
We were relying on the BIOS to set these bits, which doesn't always
happen.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 9cbb0cd..c22823b 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1777,6 +1777,26 @@
POSTING_READ(SDEIER);
}
+/*
+ * Enable digital hotplug on the PCH, and configure the DP short pulse
+ * duration to 2ms (which is the minimum in the Display Port spec)
+ *
+ * This register is the same on all known PCH chips.
+ */
+
+static void ironlake_enable_pch_hotplug(struct drm_device *dev)
+{
+ drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+ u32 hotplug;
+
+ hotplug = I915_READ(PCH_PORT_HOTPLUG);
+ hotplug &= ~(PORTD_PULSE_DURATION_MASK|PORTC_PULSE_DURATION_MASK|PORTB_PULSE_DURATION_MASK);
+ hotplug |= PORTD_HOTPLUG_ENABLE | PORTD_PULSE_DURATION_2ms;
+ hotplug |= PORTC_HOTPLUG_ENABLE | PORTC_PULSE_DURATION_2ms;
+ hotplug |= PORTB_HOTPLUG_ENABLE | PORTB_PULSE_DURATION_2ms;
+ I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
+}
+
static int ironlake_irq_postinstall(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
@@ -1839,6 +1859,8 @@
I915_WRITE(SDEIER, hotplug_mask);
POSTING_READ(SDEIER);
+ ironlake_enable_pch_hotplug(dev);
+
if (IS_IRONLAKE_M(dev)) {
/* Clear & enable PCU event interrupts */
I915_WRITE(DEIIR, DE_PCU_EVENT);
@@ -1896,6 +1918,8 @@
I915_WRITE(SDEIER, hotplug_mask);
POSTING_READ(SDEIER);
+ ironlake_enable_pch_hotplug(dev);
+
return 0;
}