drm/i915: Add suspend count to error state

For example if we get bug reports with similar error states and
suspend count is always 1, that might lead the Sherlocks to
right general direction.
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -479,6 +479,8 @@ static int i915_drm_freeze(struct drm_device *dev)
 	intel_fbdev_set_suspend(dev, FBINFO_STATE_SUSPENDED);
 	console_unlock();
 
+	dev_priv->suspend_count++;
+
 	return 0;
 }
 

drivers/gpu/drm/i915/i915_drv.h

@@ -305,6 +305,7 @@ struct drm_i915_error_state {
 
 	char error_msg[128];
 	u32 reset_count;
+	u32 suspend_count;
 
 	/* Generic register state */
 	u32 eir;
@@ -1606,6 +1607,8 @@ typedef struct drm_i915_private {
 	struct i915_dri1_state dri1;
 	/* Old ums support infrastructure, same warning applies. */
 	struct i915_ums_state ums;
+
+	u32 suspend_count;
 } drm_i915_private_t;
 
 static inline struct drm_i915_private *to_i915(const struct drm_device *dev)

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -348,6 +348,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 		}
 	}
 	err_printf(m, "Reset count: %u\n", error->reset_count);
+	err_printf(m, "Suspend count: %u\n", error->suspend_count);
 	err_printf(m, "PCI ID: 0x%04x\n", dev->pdev->device);
 	err_printf(m, "EIR: 0x%08x\n", error->eir);
 	err_printf(m, "IER: 0x%08x\n", error->ier);
@@ -1125,6 +1126,7 @@ static void i915_capture_gen_state(struct drm_i915_private *dev_priv,
 				   struct drm_i915_error_state *error)
 {
 	error->reset_count = i915_reset_count(&dev_priv->gpu_error);
+	error->suspend_count = dev_priv->suspend_count;
 }
 
 /**