Re: [PATCH V3] accel/amdxdna: Prevent PM resume deadlock in hwctx_sync_debug_bo()

[Max Zhen]

On 6/16/2026 Tue 14:24, Lizhi Hou wrote:

amdxdna_hwctx_sync_debug_bo() invokes the hardware hwctx_sync_debug_bo()
callback while holding xdna->dev_lock.

The callback may call amdxdna_cmd_submit(), which in turn calls
amdxdna_pm_resume_get(). If the device is suspended,
amdxdna_pm_resume_get() may synchronously execute amdxdna_pm_resume(),
which also acquires xdna->dev_lock, resulting in a deadlock.

Avoid the deadlock by calling amdxdna_pm_resume_get() before holding
xdna->dev_lock in both amdxdna_hwctx_sync_debug_bo() and
amdxdna_drm_config_hwctx_ioctl()

Fixes: 7ea046838021 ("accel/amdxdna: Support firmware debug buffer")
Signed-off-by: Lizhi Hou <lizhi....@amd.com>

Reviewed-by: Max Zhen <max.z...@amd.com>

---
V2:
   Fix jumping forward over the guard(mutex) declaration.
V3:
   Fix the same in amdxdna_drm_config_hwctx_ioctl().

  drivers/accel/amdxdna/amdxdna_ctx.c | 26 ++++++++++++++++++++++----
  1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/accel/amdxdna/amdxdna_ctx.c 
b/drivers/accel/amdxdna/amdxdna_ctx.c
index ff6c3e8e5a15..2ab4443e7094 100644
--- a/drivers/accel/amdxdna/amdxdna_ctx.c
+++ b/drivers/accel/amdxdna/amdxdna_ctx.c
@@ -356,16 +356,25 @@ int amdxdna_drm_config_hwctx_ioctl(struct drm_device 
*dev, void *data, struct dr
                return -EINVAL;
        }

- guard(mutex)(&xdna->dev_lock);

+       ret = amdxdna_pm_resume_get(xdna);
+       if (ret) {
+               XDNA_ERR(xdna, "Resume failed, ret %d", ret);
+               goto free_buf;
+       }
+
+       mutex_lock(&xdna->dev_lock);
        hwctx = xa_load(&client->hwctx_xa, args->handle);
        if (!hwctx) {
                XDNA_DBG(xdna, "PID %d failed to get hwctx %d", client->pid, 
args->handle);
                ret = -EINVAL;
-               goto free_buf;
+               goto unlock;
        }

ret = xdna->dev_info->ops->hwctx_config(hwctx, args->param_type, val, buf, buf_size); +unlock:

+       mutex_unlock(&xdna->dev_lock);
+       amdxdna_pm_suspend_put(xdna);
  free_buf:
        kfree(buf);
        return ret;
@@ -386,16 +395,25 @@ int amdxdna_hwctx_sync_debug_bo(struct amdxdna_client 
*client, u32 debug_bo_hdl)
        if (!gobj)
                return -EINVAL;

+ ret = amdxdna_pm_resume_get(xdna);

+       if (ret) {
+               XDNA_ERR(xdna, "Resume failed, ret %d", ret);
+               goto put_obj;
+       }
+
        abo = to_xdna_obj(gobj);
-       guard(mutex)(&xdna->dev_lock);
+       mutex_lock(&xdna->dev_lock);
        hwctx = xa_load(&client->hwctx_xa, abo->assigned_hwctx);
        if (!hwctx) {
                ret = -EINVAL;
-               goto put_obj;
+               goto unlock;
        }

ret = xdna->dev_info->ops->hwctx_sync_debug_bo(hwctx, debug_bo_hdl); +unlock:

+       mutex_unlock(&xdna->dev_lock);
+       amdxdna_pm_suspend_put(xdna);
  put_obj:
        drm_gem_object_put(gobj);
        return ret;