drm/amdgpu: drop the busy wait for GMC v9 TLB invalidations

This code is not performance critical.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Emily Deng <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 4 insertions, 22 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index 4845b6af5808..14ca4d835e0b 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -350,35 +350,17 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev,
                 }
 
                 spin_lock(&adev->gmc.invalidate_lock);
-
                 WREG32_NO_KIQ(hub->vm_inv_eng0_req + eng, tmp);
-
-                /* Busy wait for ACK.*/
-                for (j = 0; j < 100; j++) {
-                        tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_ack + eng);
-                        tmp &= 1 << vmid;
-                        if (tmp)
-                                break;
-                        cpu_relax();
-                }
-                if (j < 100) {
-                        spin_unlock(&adev->gmc.invalidate_lock);
-                        continue;
-                }
-
-                /* Wait for ACK with a delay.*/
                 for (j = 0; j < adev->usec_timeout; j++) {
                         tmp = RREG32_NO_KIQ(hub->vm_inv_eng0_ack + eng);
-                        tmp &= 1 << vmid;
-                        if (tmp)
+                        if (tmp & (1 << vmid))
                                 break;
                         udelay(1);
                 }
-                if (j < adev->usec_timeout) {
-                        spin_unlock(&adev->gmc.invalidate_lock);
-                        continue;
-                }
                 spin_unlock(&adev->gmc.invalidate_lock);
+                if (j < adev->usec_timeout)
+                        continue;
+
                 DRM_ERROR("Timeout waiting for VM flush ACK!\n");
         }
 }