[Intel-gfx] [PATCH 18/17] drm/i915: Don't call intel_get_hpd_pins() when there's no hotplug interrupt

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

On GMCH plaforms we are now getting the following spew on aux
interrupts:
[drm:intel_get_hpd_pins] hotplug event received, stat 0x00000000, dig 0x00000000, pins 0x00000000
[drm:intel_get_hpd_pins] hotplug event received, stat 0x00000000, dig 0x00000000, pins 0x00000000
[drm:intel_get_hpd_pins] hotplug event received, stat 0x00000000, dig 0x00000000, pins 0x00000000
[drm:intel_get_hpd_pins] hotplug event received, stat 0x00000000, dig 0x00000000, pins 0x00000000
[drm:intel_get_hpd_pins] hotplug event received, stat 0x00000000, dig 0x00000000, pins 0x00000000
[drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064

Prevent it by not calling intel_get_hpd_pins() unless one of the HPD
interrupt bits are actually set.

I already fixed similar annoyance once with
4bca26d0a6518d51a9abe64fbde4b12f04c74053 drm/i915: Use HOTPLUG_INT_STATUS_G4X on VLV/CHV

but another source for it got added in
fd63e2a972c670887e5e8a08440111d3812c0996 drm/i915: combine i9xx_get_hpd_pins and pch_get_hpd_pins

due to pch_get_hpd_pins() being chosen over i9xx_get_hpd_pins() to
serve as the new unified piece of code. pch_get_hpd_pins() had the debug
print, and i9xx_get_hpd_pins() didn't.

Cc: Imre Deak <imre.deak at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 610d301..07e539d 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1639,20 +1639,26 @@ static void i9xx_hpd_irq_handler(struct drm_device *dev)
 	if (IS_G4X(dev) || IS_VALLEYVIEW(dev)) {
 		u32 hotplug_trigger = hotplug_status & HOTPLUG_INT_STATUS_G4X;
 
-		intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
-				   hotplug_trigger, hpd_status_g4x,
-				   i9xx_port_hotplug_long_detect);
-		intel_hpd_irq_handler(dev, pin_mask, long_mask);
+		if (hotplug_trigger) {
+			intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
+					   hotplug_trigger, hpd_status_g4x,
+					   i9xx_port_hotplug_long_detect);
+
+			intel_hpd_irq_handler(dev, pin_mask, long_mask);
+		}
 
 		if (hotplug_status & DP_AUX_CHANNEL_MASK_INT_STATUS_G4X)
 			dp_aux_irq_handler(dev);
 	} else {
 		u32 hotplug_trigger = hotplug_status & HOTPLUG_INT_STATUS_I915;
 
-		intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
-				   hotplug_trigger, hpd_status_i915,
-				   i9xx_port_hotplug_long_detect);
-		intel_hpd_irq_handler(dev, pin_mask, long_mask);
+		if (hotplug_trigger) {
+			intel_get_hpd_pins(&pin_mask, &long_mask, hotplug_trigger,
+					   hotplug_trigger, hpd_status_i915,
+					   i9xx_port_hotplug_long_detect);
+
+			intel_hpd_irq_handler(dev, pin_mask, long_mask);
+		}
 	}
 }
 
-- 
2.4.6