Commit 742cbee8 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm/i915: rework dev->first_error locking 



- reduce the irq disabled section, even for a debugfs file this was
  way too long.
- always disable irqs when taking the lock.

v2: Thou shalt not mistake locking for reference counting, so:
- reference count the error_state to protect from concurent freeeing.
  This will be only really used in the next patch.

Reviewed-by: default avatarEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent e5eb3d63

drivers/gpu/drm/i915/i915_debugfs.c

+8 −5
Original line number Diff line number Diff line
@@ -698,12 +698,16 @@ static int i915_error_state(struct seq_file *m, void *unused) 
	int i, j, page, offset, elt;



	spin_lock_irqsave(&dev_priv->error_lock, flags);

	if (!dev_priv->first_error) {

	error = dev_priv->first_error;

	if (error)

		kref_get(&error->ref);

	spin_unlock_irqrestore(&dev_priv->error_lock, flags);



	if (!error) {

		seq_printf(m, "no error state collected\n");

		goto out;

		return 0;

	}



	error = dev_priv->first_error;



	seq_printf(m, "Time: %ld s %ld us\n", error->time.tv_sec,

		   error->time.tv_usec);
@@ -786,8 +790,7 @@ static int i915_error_state(struct seq_file *m, void *unused) 
	if (error->display)

		intel_display_print_error_state(m, dev, error->display);



out:

	spin_unlock_irqrestore(&dev_priv->error_lock, flags);

	kref_put(&error->ref, i915_error_state_free);



	return 0;

}

drivers/gpu/drm/i915/i915_drv.h

+5 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include <drm/intel-gtt.h>

#include <linux/backlight.h>

#include <linux/intel-iommu.h>

#include <linux/kref.h>



/* General customization:

 */
@@ -171,6 +172,7 @@ struct sdvo_device_mapping { 
struct intel_display_error_state;



struct drm_i915_error_state {

	struct kref ref;

	u32 eir;

	u32 pgtbl_er;

	u32 ier;
@@ -465,6 +467,7 @@ typedef struct drm_i915_private { 
	unsigned int fsb_freq, mem_freq, is_ddr3;



	spinlock_t error_lock;

	/* Protected by dev->error_lock. */

	struct drm_i915_error_state *first_error;

	struct work_struct error_work;

	struct completion error_completion;
@@ -1163,6 +1166,8 @@ void i915_handle_error(struct drm_device *dev, bool wedged); 


extern void intel_irq_init(struct drm_device *dev);



void i915_error_state_free(struct kref *error_ref);



void

i915_enable_pipestat(drm_i915_private_t *dev_priv, int pipe, u32 mask);

drivers/gpu/drm/i915/i915_irq.c

+7 −5
Original line number Diff line number Diff line
@@ -850,10 +850,11 @@ i915_error_object_free(struct drm_i915_error_object *obj) 
	kfree(obj);

}



static void

i915_error_state_free(struct drm_device *dev,

		      struct drm_i915_error_state *error)

void

i915_error_state_free(struct kref *error_ref)

{

	struct drm_i915_error_state *error = container_of(error_ref,

							  typeof(*error), ref);

	int i;



	for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
@@ -1102,6 +1103,7 @@ static void i915_capture_error_state(struct drm_device *dev) 
	DRM_INFO("capturing error event; look for more information in /debug/dri/%d/i915_error_state\n",

		 dev->primary->index);



	kref_init(&error->ref);

	error->eir = I915_READ(EIR);

	error->pgtbl_er = I915_READ(PGTBL_ER);
@@ -1173,7 +1175,7 @@ static void i915_capture_error_state(struct drm_device *dev) 
	spin_unlock_irqrestore(&dev_priv->error_lock, flags);



	if (error)

		i915_error_state_free(dev, error);

		i915_error_state_free(&error->ref);

}



void i915_destroy_error_state(struct drm_device *dev)
@@ -1188,7 +1190,7 @@ void i915_destroy_error_state(struct drm_device *dev) 
	spin_unlock_irqrestore(&dev_priv->error_lock, flags);



	if (error)

		i915_error_state_free(dev, error);

		kref_put(&error->ref, i915_error_state_free);

}

#else

#define i915_capture_error_state(x)

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