[PATCH 07/10] drm/radeon: apply Murphy's law to the kms irq code

Christian König deathsimple at vodafone.de
Thu May 24 00:49:11 PDT 2012


From: Christian Koenig <christian.koenig at amd.com>

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.

Signed-off-by: Christian Koenig <christian.koenig at amd.com>
---
 drivers/gpu/drm/radeon/evergreen.c      |    1 -
 drivers/gpu/drm/radeon/r100.c           |    1 -
 drivers/gpu/drm/radeon/r600.c           |    1 -
 drivers/gpu/drm/radeon/r600_hdmi.c      |    6 +--
 drivers/gpu/drm/radeon/radeon.h         |   33 +++++++-------
 drivers/gpu/drm/radeon/radeon_irq_kms.c |   72 +++++++++++++++++++++++++------
 drivers/gpu/drm/radeon/radeon_kms.c     |   12 ++++--
 drivers/gpu/drm/radeon/radeon_pm.c      |   12 +-----
 drivers/gpu/drm/radeon/rs600.c          |    1 -
 drivers/gpu/drm/radeon/si.c             |    1 -
 10 files changed, 90 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index bfcb39e..9e9b3bb 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -3254,7 +3254,6 @@ restart_ih:
 			break;
 		case 233: /* GUI IDLE */
 			DRM_DEBUG("IH: GUI idle\n");
-			rdev->pm.gui_idle = true;
 			wake_up(&rdev->irq.idle_queue);
 			break;
 		default:
diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 415b7d8..2587426 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -782,7 +782,6 @@ int r100_irq_process(struct radeon_device *rdev)
 		/* gui idle interrupt */
 		if (status & RADEON_GUI_IDLE_STAT) {
 			rdev->irq.gui_idle_acked = true;
-			rdev->pm.gui_idle = true;
 			wake_up(&rdev->irq.idle_queue);
 		}
 		/* Vertical blank interrupts */
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index eadbb06..90c6639 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3542,7 +3542,6 @@ restart_ih:
 			break;
 		case 233: /* GUI IDLE */
 			DRM_DEBUG("IH: GUI idle\n");
-			rdev->pm.gui_idle = true;
 			wake_up(&rdev->irq.idle_queue);
 			break;
 		default:
diff --git a/drivers/gpu/drm/radeon/r600_hdmi.c b/drivers/gpu/drm/radeon/r600_hdmi.c
index 226379e..b76c0f2 100644
--- a/drivers/gpu/drm/radeon/r600_hdmi.c
+++ b/drivers/gpu/drm/radeon/r600_hdmi.c
@@ -523,8 +523,7 @@ void r600_hdmi_enable(struct drm_encoder *encoder)
 
 	if (rdev->irq.installed) {
 		/* if irq is available use it */
-		rdev->irq.afmt[dig->afmt->id] = true;
-		radeon_irq_set(rdev);
+		radeon_irq_kms_enable_afmt(rdev, dig->afmt->id);
 	}
 
 	dig->afmt->enabled = true;
@@ -560,8 +559,7 @@ void r600_hdmi_disable(struct drm_encoder *encoder)
 		  offset, radeon_encoder->encoder_id);
 
 	/* disable irq */
-	rdev->irq.afmt[dig->afmt->id] = false;
-	radeon_irq_set(rdev);
+	radeon_irq_kms_disable_afmt(rdev, dig->afmt->id);
 
 	/* Older chipsets not handled by AtomBIOS */
 	if (rdev->family >= CHIP_R600 && !ASIC_IS_DCE3(rdev)) {
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 8479096..23552b4 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -610,21 +610,20 @@ union radeon_irq_stat_regs {
 #define RADEON_MAX_AFMT_BLOCKS 6
 
 struct radeon_irq {
-	bool		installed;
-	bool		sw_int[RADEON_NUM_RINGS];
-	bool		crtc_vblank_int[RADEON_MAX_CRTCS];
-	bool		pflip[RADEON_MAX_CRTCS];
-	wait_queue_head_t	vblank_queue;
-	bool            hpd[RADEON_MAX_HPD_PINS];
-	bool            gui_idle;
-	bool            gui_idle_acked;
-	wait_queue_head_t	idle_queue;
-	bool		afmt[RADEON_MAX_AFMT_BLOCKS];
-	spinlock_t sw_lock;
-	int sw_refcount[RADEON_NUM_RINGS];
-	union radeon_irq_stat_regs stat_regs;
-	spinlock_t pflip_lock[RADEON_MAX_CRTCS];
-	int pflip_refcount[RADEON_MAX_CRTCS];
+	bool				installed;
+	spinlock_t			lock;
+	bool				sw_int[RADEON_NUM_RINGS];
+	int				sw_refcount[RADEON_NUM_RINGS];
+	bool				crtc_vblank_int[RADEON_MAX_CRTCS];
+	bool				pflip[RADEON_MAX_CRTCS];
+	int				pflip_refcount[RADEON_MAX_CRTCS];
+	wait_queue_head_t		vblank_queue;
+	bool				hpd[RADEON_MAX_HPD_PINS];
+	bool				gui_idle;
+	bool				gui_idle_acked;
+	wait_queue_head_t		idle_queue;
+	bool				afmt[RADEON_MAX_AFMT_BLOCKS];
+	union radeon_irq_stat_regs	stat_regs;
 };
 
 int radeon_irq_kms_init(struct radeon_device *rdev);
@@ -633,6 +632,9 @@ void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring);
 void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring);
 void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc);
 void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc);
+void radeon_irq_kms_enable_afmt(struct radeon_device *rdev, int block);
+void radeon_irq_kms_disable_afmt(struct radeon_device *rdev, int block);
+int radeon_irq_kms_wait_gui_idle(struct radeon_device *rdev);
 
 /*
  * CP & rings.
@@ -1058,7 +1060,6 @@ struct radeon_pm {
 	int			active_crtc_count;
 	int			req_vblank;
 	bool			vblank_sync;
-	bool			gui_idle;
 	fixed20_12		max_bandwidth;
 	fixed20_12		igp_sideport_mclk;
 	fixed20_12		igp_system_mclk;
diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 5df58d1..11fc4f7 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -32,6 +32,8 @@
 #include "radeon.h"
 #include "atom.h"
 
+#define RADEON_WAIT_IDLE_TIMEOUT 200
+
 irqreturn_t radeon_driver_irq_handler_kms(DRM_IRQ_ARGS)
 {
 	struct drm_device *dev = (struct drm_device *) arg;
@@ -62,8 +64,10 @@ static void radeon_hotplug_work_func(struct work_struct *work)
 void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
+	unsigned long irqflags;
 	unsigned i;
 
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	/* Disable *all* interrupts */
 	for (i = 0; i < RADEON_NUM_RINGS; i++)
 		rdev->irq.sw_int[i] = false;
@@ -76,6 +80,7 @@ void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 		rdev->irq.afmt[i] = false;
 	}
 	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 	/* Clear bits */
 	radeon_irq_process(rdev);
 }
@@ -83,23 +88,28 @@ void radeon_driver_irq_preinstall_kms(struct drm_device *dev)
 int radeon_driver_irq_postinstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
+	unsigned long irqflags;
 	unsigned i;
 
 	dev->max_vblank_count = 0x001fffff;
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	for (i = 0; i < RADEON_NUM_RINGS; i++)
 		rdev->irq.sw_int[i] = true;
 	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 	return 0;
 }
 
 void radeon_driver_irq_uninstall_kms(struct drm_device *dev)
 {
 	struct radeon_device *rdev = dev->dev_private;
+	unsigned long irqflags;
 	unsigned i;
 
 	if (rdev == NULL) {
 		return;
 	}
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	/* Disable *all* interrupts */
 	for (i = 0; i < RADEON_NUM_RINGS; i++)
 		rdev->irq.sw_int[i] = false;
@@ -112,6 +122,7 @@ void radeon_driver_irq_uninstall_kms(struct drm_device *dev)
 		rdev->irq.afmt[i] = false;
 	}
 	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
 static bool radeon_msi_ok(struct radeon_device *rdev)
@@ -168,15 +179,12 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
 
 int radeon_irq_kms_init(struct radeon_device *rdev)
 {
-	int i;
 	int r = 0;
 
 	INIT_WORK(&rdev->hotplug_work, radeon_hotplug_work_func);
 	INIT_WORK(&rdev->audio_work, r600_audio_update_hdmi);
 
-	spin_lock_init(&rdev->irq.sw_lock);
-	for (i = 0; i < rdev->num_crtc; i++)
-		spin_lock_init(&rdev->irq.pflip_lock[i]);
+	spin_lock_init(&rdev->irq.lock);
 	r = drm_vblank_init(rdev->ddev, rdev->num_crtc);
 	if (r) {
 		return r;
@@ -217,25 +225,25 @@ void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
 
-	spin_lock_irqsave(&rdev->irq.sw_lock, irqflags);
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	if (rdev->ddev->irq_enabled && (++rdev->irq.sw_refcount[ring] == 1)) {
 		rdev->irq.sw_int[ring] = true;
 		radeon_irq_set(rdev);
 	}
-	spin_unlock_irqrestore(&rdev->irq.sw_lock, irqflags);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
 void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
 
-	spin_lock_irqsave(&rdev->irq.sw_lock, irqflags);
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	BUG_ON(rdev->ddev->irq_enabled && rdev->irq.sw_refcount[ring] <= 0);
 	if (rdev->ddev->irq_enabled && (--rdev->irq.sw_refcount[ring] == 0)) {
 		rdev->irq.sw_int[ring] = false;
 		radeon_irq_set(rdev);
 	}
-	spin_unlock_irqrestore(&rdev->irq.sw_lock, irqflags);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
 void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc)
@@ -245,12 +253,12 @@ void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc)
 	if (crtc < 0 || crtc >= rdev->num_crtc)
 		return;
 
-	spin_lock_irqsave(&rdev->irq.pflip_lock[crtc], irqflags);
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	if (rdev->ddev->irq_enabled && (++rdev->irq.pflip_refcount[crtc] == 1)) {
 		rdev->irq.pflip[crtc] = true;
 		radeon_irq_set(rdev);
 	}
-	spin_unlock_irqrestore(&rdev->irq.pflip_lock[crtc], irqflags);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
 void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc)
@@ -260,12 +268,52 @@ void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc)
 	if (crtc < 0 || crtc >= rdev->num_crtc)
 		return;
 
-	spin_lock_irqsave(&rdev->irq.pflip_lock[crtc], irqflags);
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	BUG_ON(rdev->ddev->irq_enabled && rdev->irq.pflip_refcount[crtc] <= 0);
 	if (rdev->ddev->irq_enabled && (--rdev->irq.pflip_refcount[crtc] == 0)) {
 		rdev->irq.pflip[crtc] = false;
 		radeon_irq_set(rdev);
 	}
-	spin_unlock_irqrestore(&rdev->irq.pflip_lock[crtc], irqflags);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
+}
+
+void radeon_irq_kms_enable_afmt(struct radeon_device *rdev, int block)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
+	rdev->irq.afmt[block] = true;
+	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
+
+}
+
+void radeon_irq_kms_disable_afmt(struct radeon_device *rdev, int block)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
+	rdev->irq.afmt[block] = false;
+	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
+int radeon_irq_kms_wait_gui_idle(struct radeon_device *rdev)
+{
+	unsigned long irqflags;
+	int r;
+
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
+	rdev->irq.gui_idle = true;
+	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
+
+	r = wait_event_timeout(rdev->irq.idle_queue, radeon_gui_idle(rdev),
+			       msecs_to_jiffies(RADEON_WAIT_IDLE_TIMEOUT));
+
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
+	rdev->irq.gui_idle = false;
+	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
+	return r;
+}
diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index f1016a5..abbb04d 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -382,29 +382,35 @@ u32 radeon_get_vblank_counter_kms(struct drm_device *dev, int crtc)
 int radeon_enable_vblank_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
+	unsigned long irqflags;
+	int r;
 
 	if (crtc < 0 || crtc >= rdev->num_crtc) {
 		DRM_ERROR("Invalid crtc %d\n", crtc);
 		return -EINVAL;
 	}
 
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	rdev->irq.crtc_vblank_int[crtc] = true;
-
-	return radeon_irq_set(rdev);
+	r = radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
+	return r;
 }
 
 void radeon_disable_vblank_kms(struct drm_device *dev, int crtc)
 {
 	struct radeon_device *rdev = dev->dev_private;
+	unsigned long irqflags;
 
 	if (crtc < 0 || crtc >= rdev->num_crtc) {
 		DRM_ERROR("Invalid crtc %d\n", crtc);
 		return;
 	}
 
+	spin_lock_irqsave(&rdev->irq.lock, irqflags);
 	rdev->irq.crtc_vblank_int[crtc] = false;
-
 	radeon_irq_set(rdev);
+	spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
 }
 
 int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index d13b6ae..79642cd 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -34,7 +34,6 @@
 #define RADEON_IDLE_LOOP_MS 100
 #define RADEON_RECLOCK_DELAY_MS 200
 #define RADEON_WAIT_VBLANK_TIMEOUT 200
-#define RADEON_WAIT_IDLE_TIMEOUT 200
 
 static const char *radeon_pm_state_type_name[5] = {
 	"Default",
@@ -257,15 +256,8 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev)
 	/* gui idle int has issues on older chips it seems */
 	if (rdev->family >= CHIP_R600) {
 		if (rdev->irq.installed) {
-			/* wait for GPU idle */
-			rdev->pm.gui_idle = false;
-			rdev->irq.gui_idle = true;
-			radeon_irq_set(rdev);
-			wait_event_interruptible_timeout(
-				rdev->irq.idle_queue, rdev->pm.gui_idle,
-				msecs_to_jiffies(RADEON_WAIT_IDLE_TIMEOUT));
-			rdev->irq.gui_idle = false;
-			radeon_irq_set(rdev);
+			/* wait for GPU to become idle */
+			radeon_irq_kms_wait_gui_idle(rdev);
 		}
 	} else {
 		struct radeon_ring *ring = &rdev->ring[RADEON_RING_TYPE_GFX_INDEX];
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index 25f9eef..4e9c41a 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -686,7 +686,6 @@ int rs600_irq_process(struct radeon_device *rdev)
 		/* 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 */
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index f969487..23be691 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -3773,7 +3773,6 @@ restart_ih:
 			break;
 		case 233: /* GUI IDLE */
 			DRM_DEBUG("IH: GUI idle\n");
-			rdev->pm.gui_idle = true;
 			wake_up(&rdev->irq.idle_queue);
 			break;
 		default:
-- 
1.7.9.5



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