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drm/radeon: fix & improve ih ring handling v3 

The spinlock was actually there to protect the
rptr, but rptr was read outside of the locked area.

Also we don't really need a spinlock here, an
atomic should to quite fine since we only need to
prevent it from being reentrant.

v2: Keep the spinlock....
v3: Back to an atomic again after finding & fixing the real bug.

Signed-off-by: Christian Koenig <christian.koenig@amd.com>
This commit is contained in:
Christian Koenig 2012-05-16 21:45:24 +02:00 committed by Christian König
parent 6823d74003
commit c20dc3698d
5 changed files with 41 additions and 47 deletions
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26
drivers/gpu/drm/radeon/evergreen.c
View File

@ -2676,7 +2676,6 @@ int evergreen_irq_process(struct radeon_device *rdev)
u32 rptr;
u32 src_id, src_data;
u32 ring_index;
unsigned long flags;
bool queue_hotplug = false;
bool queue_hdmi = false;
@ -2684,22 +2683,21 @@ int evergreen_irq_process(struct radeon_device *rdev)
return IRQ_NONE;
wptr = evergreen_get_ih_wptr(rdev);
restart_ih:
/* is somebody else already processing irqs? */
if (atomic_xchg(&rdev->ih.lock, 1))
return IRQ_NONE;
rptr = rdev->ih.rptr;
DRM_DEBUG("r600_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
spin_lock_irqsave(&rdev->ih.lock, flags);
if (rptr == wptr) {
spin_unlock_irqrestore(&rdev->ih.lock, flags);
return IRQ_NONE;
}
restart_ih:
/* Order reading of wptr vs. reading of IH ring data */
rmb();
/* display interrupts */
evergreen_irq_ack(rdev);
rdev->ih.wptr = wptr;
while (rptr != wptr) {
/* wptr/rptr are in bytes! */
ring_index = rptr / 4;
@ -2998,17 +2996,19 @@ restart_ih:
rptr += 16;
rptr &= rdev->ih.ptr_mask;
}
/* make sure wptr hasn't changed while processing */
wptr = evergreen_get_ih_wptr(rdev);
if (wptr != rdev->ih.wptr)
goto restart_ih;
if (queue_hotplug)
schedule_work(&rdev->hotplug_work);
if (queue_hdmi)
schedule_work(&rdev->audio_work);
rdev->ih.rptr = rptr;
WREG32(IH_RB_RPTR, rdev->ih.rptr);
spin_unlock_irqrestore(&rdev->ih.lock, flags);
atomic_set(&rdev->ih.lock, 0);
/* make sure wptr hasn't changed while processing */
wptr = evergreen_get_ih_wptr(rdev);
if (wptr != rptr)
goto restart_ih;
return IRQ_HANDLED;
}

29
drivers/gpu/drm/radeon/r600.c
View File

@ -2858,7 +2858,6 @@ void r600_disable_interrupts(struct radeon_device *rdev)
WREG32(IH_RB_RPTR, 0);
WREG32(IH_RB_WPTR, 0);
rdev->ih.enabled = false;
rdev->ih.wptr = 0;
rdev->ih.rptr = 0;
}
@ -3310,7 +3309,6 @@ int r600_irq_process(struct radeon_device *rdev)
u32 rptr;
u32 src_id, src_data;
u32 ring_index;
unsigned long flags;
bool queue_hotplug = false;
bool queue_hdmi = false;
@ -3322,24 +3320,21 @@ int r600_irq_process(struct radeon_device *rdev)
RREG32(IH_RB_WPTR);
wptr = r600_get_ih_wptr(rdev);
restart_ih:
/* is somebody else already processing irqs? */
if (atomic_xchg(&rdev->ih.lock, 1))
return IRQ_NONE;
rptr = rdev->ih.rptr;
DRM_DEBUG("r600_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
spin_lock_irqsave(&rdev->ih.lock, flags);
if (rptr == wptr) {
spin_unlock_irqrestore(&rdev->ih.lock, flags);
return IRQ_NONE;
}
restart_ih:
/* Order reading of wptr vs. reading of IH ring data */
rmb();
/* display interrupts */
r600_irq_ack(rdev);
rdev->ih.wptr = wptr;
while (rptr != wptr) {
/* wptr/rptr are in bytes! */
ring_index = rptr / 4;
@ -3493,17 +3488,19 @@ restart_ih:
rptr += 16;
rptr &= rdev->ih.ptr_mask;
}
/* make sure wptr hasn't changed while processing */
wptr = r600_get_ih_wptr(rdev);
if (wptr != rdev->ih.wptr)
goto restart_ih;
if (queue_hotplug)
schedule_work(&rdev->hotplug_work);
if (queue_hdmi)
schedule_work(&rdev->audio_work);
rdev->ih.rptr = rptr;
WREG32(IH_RB_RPTR, rdev->ih.rptr);
spin_unlock_irqrestore(&rdev->ih.lock, flags);
atomic_set(&rdev->ih.lock, 0);
/* make sure wptr hasn't changed while processing */
wptr = r600_get_ih_wptr(rdev);
if (wptr != rptr)
goto restart_ih;
return IRQ_HANDLED;
}

3
drivers/gpu/drm/radeon/radeon.h
View File

@ -738,11 +738,10 @@ struct r600_ih {
struct radeon_bo *ring_obj;
volatile uint32_t *ring;
unsigned rptr;
unsigned wptr;
unsigned ring_size;
uint64_t gpu_addr;
uint32_t ptr_mask;
spinlock_t lock;
atomic_t lock;
bool enabled;
};

3
drivers/gpu/drm/radeon/radeon_device.c
View File

@ -731,8 +731,7 @@ int radeon_device_init(struct radeon_device *rdev,
radeon_mutex_init(&rdev->cs_mutex);
mutex_init(&rdev->ring_lock);
mutex_init(&rdev->dc_hw_i2c_mutex);
if (rdev->family >= CHIP_R600)
spin_lock_init(&rdev->ih.lock);
atomic_set(&rdev->ih.lock, 0);
mutex_init(&rdev->gem.mutex);
mutex_init(&rdev->pm.mutex);
init_rwsem(&rdev->pm.mclk_lock);

27
drivers/gpu/drm/radeon/si.c
View File

@ -2942,7 +2942,6 @@ static void si_disable_interrupts(struct radeon_device *rdev)
WREG32(IH_RB_RPTR, 0);
WREG32(IH_RB_WPTR, 0);
rdev->ih.enabled = false;
rdev->ih.wptr = 0;
rdev->ih.rptr = 0;
}
@ -3359,29 +3358,27 @@ int si_irq_process(struct radeon_device *rdev)
u32 rptr;
u32 src_id, src_data, ring_id;
u32 ring_index;
unsigned long flags;
bool queue_hotplug = false;
if (!rdev->ih.enabled || rdev->shutdown)
return IRQ_NONE;
wptr = si_get_ih_wptr(rdev);
restart_ih:
/* is somebody else already processing irqs? */
if (atomic_xchg(&rdev->ih.lock, 1))
return IRQ_NONE;
rptr = rdev->ih.rptr;
DRM_DEBUG("si_irq_process start: rptr %d, wptr %d\n", rptr, wptr);
spin_lock_irqsave(&rdev->ih.lock, flags);
if (rptr == wptr) {
spin_unlock_irqrestore(&rdev->ih.lock, flags);
return IRQ_NONE;
}
restart_ih:
/* Order reading of wptr vs. reading of IH ring data */
rmb();
/* display interrupts */
si_irq_ack(rdev);
rdev->ih.wptr = wptr;
while (rptr != wptr) {
/* wptr/rptr are in bytes! */
ring_index = rptr / 4;
@ -3632,15 +3629,17 @@ restart_ih:
rptr += 16;
rptr &= rdev->ih.ptr_mask;
}
/* make sure wptr hasn't changed while processing */
wptr = si_get_ih_wptr(rdev);
if (wptr != rdev->ih.wptr)
goto restart_ih;
if (queue_hotplug)
schedule_work(&rdev->hotplug_work);
rdev->ih.rptr = rptr;
WREG32(IH_RB_RPTR, rdev->ih.rptr);
spin_unlock_irqrestore(&rdev->ih.lock, flags);
atomic_set(&rdev->ih.lock, 0);
/* make sure wptr hasn't changed while processing */
wptr = si_get_ih_wptr(rdev);
if (wptr != rptr)
goto restart_ih;
return IRQ_HANDLED;
}