[PATCH v1 2/2] drm/amdgpu: delay ttm buffer func enablement on xgmi

From: Pierre-Eric Pelloux-Prayer

Date: Tue Jun 16 2026 - 08:56:42 EST


When amdgpu_init_minimal_xgmi is used, SDMA engines init
is delayed so amdgpu_ttm_enable_buffer_funcs must be
called later.

Without this, the check for num_buffer_funcs_scheds will
fail and using ttm buffer funcs later will fail.

Fixes: 3a5da695c8d1 ("drm/amdgpu: only use working sdma schedulers for ttm")
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 ++-
drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c | 2 ++
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 57e10afb4714..2e8954fa5c40 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2479,7 +2479,8 @@ static int amdgpu_device_ip_init(struct amdgpu_device *adev)
if (r)
goto init_failed;

- amdgpu_ttm_enable_buffer_funcs(adev);
+ if (amdgpu_ip_member_of_hwini(adev, AMD_IP_BLOCK_TYPE_SDMA))
+ amdgpu_ttm_enable_buffer_funcs(adev);

/* Don't init kfd if whole hive need to be reset during init */
if (adev->init_lvl->level != AMDGPU_INIT_LEVEL_MINIMAL_XGMI) {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
index faac80a8a6eb..c0dca209335e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
@@ -1663,6 +1663,8 @@ static void amdgpu_xgmi_reset_on_init_work(struct work_struct *work)
if (r && r != -EHWPOISON)
dev_err(tmp_adev->dev,
"error during bad page data initialization");
+
+ amdgpu_ttm_enable_buffer_funcs(tmp_adev);
}
}

--
2.43.0