drm/amdgpu/tonga: don't call smu_init on resume

smu_init allocates buffers and initializes them.  It does not
touch the hw.  There is no need to do it again on resume.  It
should really be part of sw_init (and smu_fini should be part
of sw_fini), but we need the firmware sizes from the other IPs
for firmware loading so we have to wait until sw init is done
for all other IPs.

Reviewed-by: Sonny Jiang <Sonny.Jiang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 19 insertions, 6 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/tonga_dpm.c b/drivers/gpu/drm/amd/amdgpu/tonga_dpm.c
index 2d5b1bd52afa..204903897b4f 100644
--- a/drivers/gpu/drm/amd/amdgpu/tonga_dpm.c
+++ b/drivers/gpu/drm/amd/amdgpu/tonga_dpm.c
@@ -81,6 +81,10 @@ static int tonga_dpm_hw_init(void *handle)
 
         mutex_lock(&adev->pm.mutex);
 
+        /* smu init only needs to be called at startup, not resume.
+         * It should be in sw_init, but requires the fw info gathered
+         * in sw_init from other IP modules.
+         */
         ret = tonga_smu_init(adev);
         if (ret) {
                 DRM_ERROR("SMU initialization failed\n");
@@ -107,6 +111,10 @@ static int tonga_dpm_hw_fini(void *handle)
         struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
         mutex_lock(&adev->pm.mutex);
+        /* smu fini only needs to be called at teardown, not suspend.
+         * It should be in sw_fini, but we put it here for symmetry
+         * with smu init.
+         */
         tonga_smu_fini(adev);
         mutex_unlock(&adev->pm.mutex);
         return 0;
@@ -114,20 +122,25 @@ static int tonga_dpm_hw_fini(void *handle)
 
 static int tonga_dpm_suspend(void *handle)
 {
-        struct amdgpu_device *adev = (struct amdgpu_device *)handle;
-
-        tonga_dpm_hw_fini(adev);
-
         return 0;
 }
 
 static int tonga_dpm_resume(void *handle)
 {
+        int ret;
         struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
-        tonga_dpm_hw_init(adev);
+        mutex_lock(&adev->pm.mutex);
 
-        return 0;
+        ret = tonga_smu_start(adev);
+        if (ret) {
+                DRM_ERROR("SMU start failed\n");
+                goto fail;
+        }
+
+fail:
+        mutex_unlock(&adev->pm.mutex);
+        return ret;
 }
 
 static int tonga_dpm_set_clockgating_state(void *handle,