drm/radeon: apply Murphy's law to the kms irq code v3

1. It is really dangerous to have more than one
   spinlock protecting the same information.

2. radeon_irq_set sometimes wasn't called with lock
   protection, so it can happen that more than one
   CPU would tamper with the irq regs at the same
   time.

3. The pm.gui_idle variable was assuming that the 3D
   engine wasn't becoming idle between testing the
   register and setting the variable. So just remove
   it and test the register directly.

v2: Also handle the hpd irq code the same way.
v3: Rename hpd parameter for clarification.

Signed-off-by: Christian Koenig <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index e95c5e6..f9aee25 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -294,6 +294,7 @@
 {
 	struct drm_device *dev = rdev->ddev;
 	struct drm_connector *connector;
+	unsigned enable = 0;
 
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		struct radeon_connector *radeon_connector = to_radeon_connector(connector);
@@ -301,26 +302,25 @@
 		case RADEON_HPD_1:
 			WREG32(R_007D00_DC_HOT_PLUG_DETECT1_CONTROL,
 			       S_007D00_DC_HOT_PLUG_DETECT1_EN(1));
-			rdev->irq.hpd[0] = true;
 			break;
 		case RADEON_HPD_2:
 			WREG32(R_007D10_DC_HOT_PLUG_DETECT2_CONTROL,
 			       S_007D10_DC_HOT_PLUG_DETECT2_EN(1));
-			rdev->irq.hpd[1] = true;
 			break;
 		default:
 			break;
 		}
+		enable |= 1 << radeon_connector->hpd.hpd;
 		radeon_hpd_set_polarity(rdev, radeon_connector->hpd.hpd);
 	}
-	if (rdev->irq.installed)
-		rs600_irq_set(rdev);
+	radeon_irq_kms_enable_hpd(rdev, enable);
 }
 
 void rs600_hpd_fini(struct radeon_device *rdev)
 {
 	struct drm_device *dev = rdev->ddev;
 	struct drm_connector *connector;
+	unsigned disable = 0;
 
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		struct radeon_connector *radeon_connector = to_radeon_connector(connector);
@@ -328,17 +328,17 @@
 		case RADEON_HPD_1:
 			WREG32(R_007D00_DC_HOT_PLUG_DETECT1_CONTROL,
 			       S_007D00_DC_HOT_PLUG_DETECT1_EN(0));
-			rdev->irq.hpd[0] = false;
 			break;
 		case RADEON_HPD_2:
 			WREG32(R_007D10_DC_HOT_PLUG_DETECT2_CONTROL,
 			       S_007D10_DC_HOT_PLUG_DETECT2_EN(0));
-			rdev->irq.hpd[1] = false;
 			break;
 		default:
 			break;
 		}
+		disable |= 1 << radeon_connector->hpd.hpd;
 	}
+	radeon_irq_kms_disable_hpd(rdev, disable);
 }
 
 int rs600_asic_reset(struct radeon_device *rdev)
@@ -686,7 +686,6 @@
 		/* GUI idle */
 		if (G_000040_GUI_IDLE(status)) {
 			rdev->irq.gui_idle_acked = true;
-			rdev->pm.gui_idle = true;
 			wake_up(&rdev->irq.idle_queue);
 		}
 		/* Vertical blank interrupts */