[PATCH v3 1/3] drm/amdgpu: don't disable ttm buffer funcs on reset

[PATCH v3 1/3] drm/amdgpu: don't disable ttm buffer funcs on reset

[Pierre-Eric Pelloux-Prayer]

Access to hw is already suspended so there are no reasons to
disable ttm buffer funcs.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 964efec0d335..b7751dde2894 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3162,8 +3162,6 @@ static int amdgpu_device_ip_suspend(struct amdgpu_device *adev)
 		amdgpu_virt_request_full_gpu(adev, false);
 	}
 
-	amdgpu_ttm_disable_buffer_funcs(adev);
-
 	r = amdgpu_device_ip_suspend_phase1(adev);
 	if (r)
 		return r;
-- 
2.43.0

[PATCH v3 2/3] drm/amdgpu: delay ttm buffer func enablement on xgmi

[Pierre-Eric Pelloux-Prayer]

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.

Given that amdgpu_ttm_enable_buffer_funcs is a no-op if
amdgpu_in_reset() returns true, the call has to occur
after the reset lock is dropped.

Fixes: 3a5da695c8d1 ("drm/amdgpu: only use working sdma schedulers for ttm")
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 +++++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c   | 3 +++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index b7751dde2894..1ec3162cb175 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2474,7 +2474,11 @@ static int amdgpu_device_ip_init(struct amdgpu_device *adev)
 	if (r)
 		goto init_failed;
 
-	amdgpu_ttm_enable_buffer_funcs(adev);
+	/* If SDMA is not brought up during hwini, the ttm buffer funcs enablement
+	 * is delayed after reset-on-init completes.
+	 */
+	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) {
@@ -5088,8 +5092,6 @@ int amdgpu_device_reinit_after_reset(struct amdgpu_reset_context *reset_context)
 				if (r)
 					goto out;
 
-				amdgpu_ttm_enable_buffer_funcs(tmp_adev);
-
 				r = amdgpu_device_ip_resume_phase3(tmp_adev);
 				if (r)
 					goto out;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
index 2725230aa5e3..45e31b3daf06 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
@@ -1380,6 +1380,9 @@ static void amdgpu_xgmi_reset_on_init_work(struct work_struct *work)
 	amdgpu_device_unlock_reset_domain(tmp_adev->reset_domain);
 
 	list_for_each_entry(tmp_adev, &hive->device_list, gmc.xgmi.head) {
+		/* Enable ttm buffers funcs after the reset lock has been dropped. */
+		amdgpu_ttm_enable_buffer_funcs(tmp_adev);
+
 		r = amdgpu_ras_init_badpage_info(tmp_adev);
 		if (r && r != -EHWPOISON)
 			dev_err(tmp_adev->dev,
-- 
2.43.0

[PATCH v3 3/3] drm/amdgpu: remove useless enable/disable of ttm buffer funcs

[Pierre-Eric Pelloux-Prayer]

amdgpu_ttm_disable_buffer_funcs and amdgpu_ttm_enable_buffer_funcs should
each only be called once per amdgpu_device: at startup and teardown.

Therefore the other calls are redundant and can be safely dropped.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 5 -----
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 1 -
 2 files changed, 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 1ec3162cb175..e966e6f7d2fa 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3379,8 +3379,6 @@ static int amdgpu_device_ip_resume(struct amdgpu_device *adev)
 
 	r = amdgpu_device_ip_resume_phase2(adev);
 
-	amdgpu_ttm_enable_buffer_funcs(adev);
-
 	if (r)
 		return r;
 
@@ -4511,8 +4509,6 @@ int amdgpu_device_suspend(struct drm_device *dev, bool notify_clients)
 	if (r)
 		goto unwind_userq;
 
-	amdgpu_ttm_disable_buffer_funcs(adev);
-
 	amdgpu_fence_driver_hw_fini(adev);
 
 	r = amdgpu_device_ip_suspend_phase2(adev);
@@ -4525,7 +4521,6 @@ int amdgpu_device_suspend(struct drm_device *dev, bool notify_clients)
 	return 0;
 
 unwind_evict:
-	amdgpu_ttm_enable_buffer_funcs(adev);
 	amdgpu_fence_driver_hw_init(adev);
 
 unwind_userq:
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 5bcb6a966941..ba99edbfe3a6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2137,7 +2137,6 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 	}
 
 	/* Change the size here instead of the init above so only lpfn is affected */
-	amdgpu_ttm_disable_buffer_funcs(adev);
 #ifdef CONFIG_64BIT
 #ifdef CONFIG_X86
 	if (adev->gmc.xgmi.connected_to_cpu)
-- 
2.43.0

Re: [PATCH v3 3/3] drm/amdgpu: remove useless enable/disable of ttm buffer funcs

[Alex Deucher]

Series still has my RB.

Alex

On Mon, Aug 10, 2026 at 8:03 AM Pierre-Eric Pelloux-Prayer
<pierre-eric.pelloux-prayer@amd.com> wrote:
>
> amdgpu_ttm_disable_buffer_funcs and amdgpu_ttm_enable_buffer_funcs should
> each only be called once per amdgpu_device: at startup and teardown.
>
> Therefore the other calls are redundant and can be safely dropped.
>
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 5 -----
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 1 -
>  2 files changed, 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 1ec3162cb175..e966e6f7d2fa 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3379,8 +3379,6 @@ static int amdgpu_device_ip_resume(struct amdgpu_device *adev)
>
>         r = amdgpu_device_ip_resume_phase2(adev);
>
> -       amdgpu_ttm_enable_buffer_funcs(adev);
> -
>         if (r)
>                 return r;
>
> @@ -4511,8 +4509,6 @@ int amdgpu_device_suspend(struct drm_device *dev, bool notify_clients)
>         if (r)
>                 goto unwind_userq;
>
> -       amdgpu_ttm_disable_buffer_funcs(adev);
> -
>         amdgpu_fence_driver_hw_fini(adev);
>
>         r = amdgpu_device_ip_suspend_phase2(adev);
> @@ -4525,7 +4521,6 @@ int amdgpu_device_suspend(struct drm_device *dev, bool notify_clients)
>         return 0;
>
>  unwind_evict:
> -       amdgpu_ttm_enable_buffer_funcs(adev);
>         amdgpu_fence_driver_hw_init(adev);
>
>  unwind_userq:
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 5bcb6a966941..ba99edbfe3a6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -2137,7 +2137,6 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>         }
>
>         /* Change the size here instead of the init above so only lpfn is affected */
> -       amdgpu_ttm_disable_buffer_funcs(adev);
>  #ifdef CONFIG_64BIT
>  #ifdef CONFIG_X86
>         if (adev->gmc.xgmi.connected_to_cpu)
> --
> 2.43.0
>