drm/v3d: Fix race-condition between DRM scheduler and IRQs

Link: #6624
Fixes: e4b5ccd ("drm/v3d: Ensure job pointer is set to NULL after job completion")
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Co-authored-by: Maíra Canal <mcanal@igalia.com>

Author: pelwell

drivers/gpu/drm/v3d/v3d_irq.c

@@ -107,8 +107,10 @@ v3d_irq(int irq, void *arg)
 
 		v3d_job_update_stats(&v3d->bin_job->base, V3D_BIN);
 		trace_v3d_bcl_irq(&v3d->drm, fence->seqno);
-		dma_fence_signal(&fence->base);
+
 		v3d->bin_job = NULL;
+		dma_fence_signal(&fence->base);
+
 		status = IRQ_HANDLED;
 	}
 
@@ -118,8 +120,10 @@ v3d_irq(int irq, void *arg)
 
 		v3d_job_update_stats(&v3d->render_job->base, V3D_RENDER);
 		trace_v3d_rcl_irq(&v3d->drm, fence->seqno);
-		dma_fence_signal(&fence->base);
+
 		v3d->render_job = NULL;
+		dma_fence_signal(&fence->base);
+
 		status = IRQ_HANDLED;
 	}
 
@@ -129,8 +133,10 @@ v3d_irq(int irq, void *arg)
 
 		v3d_job_update_stats(&v3d->csd_job->base, V3D_CSD);
 		trace_v3d_csd_irq(&v3d->drm, fence->seqno);
-		dma_fence_signal(&fence->base);
+
 		v3d->csd_job = NULL;
+		dma_fence_signal(&fence->base);
+
 		status = IRQ_HANDLED;
 	}
 
@@ -167,8 +173,10 @@ v3d_hub_irq(int irq, void *arg)
 
 		v3d_job_update_stats(&v3d->tfu_job->base, V3D_TFU);
 		trace_v3d_tfu_irq(&v3d->drm, fence->seqno);
-		dma_fence_signal(&fence->base);
+
 		v3d->tfu_job = NULL;
+		dma_fence_signal(&fence->base);
+
 		status = IRQ_HANDLED;
 	}