On Fri, Mar 12, 2021 at 02:59:06PM +0100, Christian König wrote:
Interrupts on are non-reentrant on linux. This is just an ancient leftover from radeon where irq processing was kicked of from different places.
Signed-off-by: Christian König christian.koenig@amd.com
Man you tricked me into grepping this on radeon and it looks horrible. atomic_t is unordered in linux, so whatever was built there for radeon does not wokr like a lock. It's missing all the barriers afiui. Good riddance at least for amdgpu.
Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 1 - drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c | 5 ----- drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h | 1 - 3 files changed, 7 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index a15f1b604733..886625fb464b 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -3284,7 +3284,6 @@ int amdgpu_device_init(struct amdgpu_device *adev,
/* mutex initialization are all done here so we * can recall function without having locking issues */
- atomic_set(&adev->irq.ih.lock, 0); mutex_init(&adev->firmware.mutex); mutex_init(&adev->pm.mutex); mutex_init(&adev->gfx.gpu_clock_mutex);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c index 1024065f1f03..faaa6aa2faaf 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c @@ -228,10 +228,6 @@ int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih) wptr = amdgpu_ih_get_wptr(adev, ih);
restart_ih:
/* is somebody else already processing irqs? */
if (atomic_xchg(&ih->lock, 1))
return IRQ_NONE;DRM_DEBUG("%s: rptr %d, wptr %d\n", __func__, ih->rptr, wptr);
/* Order reading of wptr vs. reading of IH ring data */
@@ -244,7 +240,6 @@ int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
amdgpu_ih_set_rptr(adev, ih); wake_up_all(&ih->wait_process);
atomic_set(&ih->lock, 0);
/* make sure wptr hasn't changed while processing */ wptr = amdgpu_ih_get_wptr(adev, ih);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h index 87ec6d20dbe0..0649b59830a5 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h @@ -64,7 +64,6 @@ struct amdgpu_ih_ring {
bool enabled; unsigned rptr;
atomic_t lock; struct amdgpu_ih_regs ih_regs;
/* For waiting on IH processing at checkpoint. */
-- 2.25.1
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