[PATCH] accel/amdxdna: fix usage_count leak when autosuspend_delay is negative

[PATCH] accel/amdxdna: fix usage_count leak when autosuspend_delay is negative

[Guangshuo Li]

amdxdna_pm_init() calls pm_runtime_use_autosuspend(), but
amdxdna_pm_fini() does not call the matching
pm_runtime_dont_use_autosuspend() when tearing down runtime PM.

If autosuspend_delay is set to a negative value while autosuspend is
enabled, the runtime PM core increments usage_count to prevent runtime
suspend. Without calling pm_runtime_dont_use_autosuspend() during
driver teardown, this reference is not dropped and usage_count remains
unbalanced.

Add the missing pm_runtime_dont_use_autosuspend() call in
amdxdna_pm_fini() before restoring the runtime PM usage reference and
forbidding runtime PM.

This issue was found by manual code inspection.

Fixes: 063db451832b ("accel/amdxdna: Enhance runtime power management")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/accel/amdxdna/amdxdna_pm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/accel/amdxdna/amdxdna_pm.c b/drivers/accel/amdxdna/amdxdna_pm.c
index b1fafddd7ad5..7dcedb7c105f 100644
--- a/drivers/accel/amdxdna/amdxdna_pm.c
+++ b/drivers/accel/amdxdna/amdxdna_pm.c
@@ -73,6 +73,7 @@ void amdxdna_pm_fini(struct amdxdna_dev *xdna)
 {
 	struct device *dev = xdna->ddev.dev;
 
+	pm_runtime_dont_use_autosuspend(dev);
 	pm_runtime_get_noresume(dev);
 	pm_runtime_forbid(dev);
 }
-- 
2.43.0

Re: [PATCH] accel/amdxdna: fix usage_count leak when autosuspend_delay is negative

[Johan Hovold]

On Fri, Aug 07, 2026 at 10:32:00PM +0800, Guangshuo Li wrote:
> amdxdna_pm_init() calls pm_runtime_use_autosuspend(), but
> amdxdna_pm_fini() does not call the matching
> pm_runtime_dont_use_autosuspend() when tearing down runtime PM.
> 
> If autosuspend_delay is set to a negative value while autosuspend is
> enabled, the runtime PM core increments usage_count to prevent runtime
> suspend. Without calling pm_runtime_dont_use_autosuspend() during
> driver teardown, this reference is not dropped and usage_count remains
> unbalanced.

As I've explained elsewhere, this is just misleading. There is no usage
count leak here as the count is balanced whenever the user re-enables
autosuspend through sysfs (by writing a non-negative timeout).

Drivers should clean up after themselves and disable autosuspend, but
this is more of a clean up than a fix and should not be backported.

You've sent upwards of 60 of these in the matter of just a few days,
some of which have even been picked up. Please send follow-ups (replies
or v2s) as soon as possible to prevent further of these from getting
merged.

> Add the missing pm_runtime_dont_use_autosuspend() call in
> amdxdna_pm_fini() before restoring the runtime PM usage reference and
> forbidding runtime PM.
> 
> This issue was found by manual code inspection.
> 
> Fixes: 063db451832b ("accel/amdxdna: Enhance runtime power management")
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>

Johan