From 742cbee8049f434d8ae7908ee56fe4cad3db2658 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 27 Apr 2012 15:17:39 +0200 Subject: [PATCH] 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: Eugeni Dodonov Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_debugfs.c | 13 ++++++++----- drivers/gpu/drm/i915/i915_drv.h | 5 +++++ drivers/gpu/drm/i915/i915_irq.c | 12 +++++++----- 3 files changed, 20 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 192b27e9046c..72c73de35065 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -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; } diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 090ec20293f2..c070a2b3f049 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -39,6 +39,7 @@ #include #include #include +#include /* 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); diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 49e5d3ec5559..8334550fccf4 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -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) -- 2.30.2