drm/amdgpu: avoid soft lockup when waiting for RLC serdes (v2)

Normally all waiting get timeout if there's one.
Release the lock and return immediately when timeout happens.

v2:
 - set the se_sh to broadcase before return

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: pding <Pixel.Ding@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 9f93e05bf97e..46ee74393454 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -3851,6 +3851,14 @@ static void gfx_v8_0_wait_for_rlc_serdes(struct amdgpu_device *adev)
                                         break;
                                 udelay(1);
                         }
+                        if (k == adev->usec_timeout) {
+                                gfx_v8_0_select_se_sh(adev, 0xffffffff,
+                                                      0xffffffff, 0xffffffff);
+                                mutex_unlock(&adev->grbm_idx_mutex);
+                                DRM_INFO("Timeout wait for RLC serdes %u,%u\n",
+                                         i, j);
+                                return;
+                        }
                 }
         }
         gfx_v8_0_select_se_sh(adev, 0xffffffff, 0xffffffff, 0xffffffff);
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index a5811e80e21b..46a0d3ef773f 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -1645,6 +1645,14 @@ static void gfx_v9_0_wait_for_rlc_serdes(struct amdgpu_device *adev)
                                         break;
                                 udelay(1);
                         }
+                        if (k == adev->usec_timeout) {
+                                gfx_v9_0_select_se_sh(adev, 0xffffffff,
+                                                      0xffffffff, 0xffffffff);
+                                mutex_unlock(&adev->grbm_idx_mutex);
+                                DRM_INFO("Timeout wait for RLC serdes %u,%u\n",
+                                         i, j);
+                                return;
+                        }
                 }
         }
         gfx_v9_0_select_se_sh(adev, 0xffffffff, 0xffffffff, 0xffffffff);