[PATCH] i2c: designware-pci: fix autosuspend cleanup during teardown

[PATCH] i2c: designware-pci: fix autosuspend cleanup during teardown

[Guangshuo Li]

i2c_dw_pci_probe() calls pm_runtime_use_autosuspend(), but
i2c_dw_pci_remove() does not call the matching
pm_runtime_dont_use_autosuspend() during teardown.

If the 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 teardown, this reference is not dropped.

The documentation for pm_runtime_use_autosuspend() also notes that it
is important to undo it with pm_runtime_dont_use_autosuspend() at
driver exit time, unless runtime PM was initially enabled with
devm_pm_runtime_enable().

Add the missing pm_runtime_dont_use_autosuspend() call to the driver
remove path.

This issue was found by manual code inspection.

Fixes: 18dbdda89f5c ("i2c-designware: Add runtime power management support")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/i2c/busses/i2c-designware-pcidrv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 468287922363..f1f4955f9a3f 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -300,6 +300,7 @@ static void i2c_dw_pci_remove(struct pci_dev *pdev)
 
 	i2c_dw_disable(dev);
 
+	pm_runtime_dont_use_autosuspend(device);
 	pm_runtime_forbid(device);
 	pm_runtime_get_noresume(device);
 
-- 
2.43.0

Re: [PATCH] i2c: designware-pci: fix autosuspend cleanup during teardown

[Mika Westerberg]

On Sun, Aug 09, 2026 at 03:30:55PM +0800, Guangshuo Li wrote:
> i2c_dw_pci_probe() calls pm_runtime_use_autosuspend(), but
> i2c_dw_pci_remove() does not call the matching
> pm_runtime_dont_use_autosuspend() during teardown.
> 
> If the 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 teardown, this reference is not dropped.
> 
> The documentation for pm_runtime_use_autosuspend() also notes that it
> is important to undo it with pm_runtime_dont_use_autosuspend() at
> driver exit time, unless runtime PM was initially enabled with
> devm_pm_runtime_enable().
> 
> Add the missing pm_runtime_dont_use_autosuspend() call to the driver
> remove path.
> 
> This issue was found by manual code inspection.
> 
> Fixes: 18dbdda89f5c ("i2c-designware: Add runtime power management support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [PATCH] i2c: designware-pci: fix autosuspend cleanup during teardown

[Krzysztof Kozlowski]

On 09/08/2026 09:30, Guangshuo Li wrote:
> i2c_dw_pci_probe() calls pm_runtime_use_autosuspend(), but
> i2c_dw_pci_remove() does not call the matching
> pm_runtime_dont_use_autosuspend() during teardown.
> 
> If the 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 teardown, this reference is not dropped.
> 
> The documentation for pm_runtime_use_autosuspend() also notes that it
> is important to undo it with pm_runtime_dont_use_autosuspend() at
> driver exit time, unless runtime PM was initially enabled with
> devm_pm_runtime_enable().
> 
> Add the missing pm_runtime_dont_use_autosuspend() call to the driver
> remove path.
> 
> This issue was found by manual code inspection.
> 
> Fixes: 18dbdda89f5c ("i2c-designware: Add runtime power management support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>

You sent vast amount of patches, all separate, making it very difficult
to track and respond in efficient way. Do not do that.

Group your work per subsystem.

You were asked to clarify and respond to incorrect fixes statement. I do
not see how you clarified and responded at all.

Best regards,
Krzysztof

Re: [PATCH] i2c: designware-pci: fix autosuspend cleanup during teardown

[Andi Shyti]

Hi Guangshuo,

On Sun, Aug 09, 2026 at 03:30:55PM +0800, Guangshuo Li wrote:
> i2c_dw_pci_probe() calls pm_runtime_use_autosuspend(), but
> i2c_dw_pci_remove() does not call the matching
> pm_runtime_dont_use_autosuspend() during teardown.
> 
> If the 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 teardown, this reference is not dropped.
> 
> The documentation for pm_runtime_use_autosuspend() also notes that it
> is important to undo it with pm_runtime_dont_use_autosuspend() at
> driver exit time, unless runtime PM was initially enabled with
> devm_pm_runtime_enable().
> 
> Add the missing pm_runtime_dont_use_autosuspend() call to the driver
> remove path.
> 
> This issue was found by manual code inspection.
> 
> Fixes: 18dbdda89f5c ("i2c-designware: Add runtime power management support")

This Fixes: is wrong because there was no autosuspend here. Maybe
you are referring to:

Fixes: 43452335224b ("i2c-designware: switch to use runtime PM autosuspend")
Cc: <stable@vger.kernel.org> # v3.10+

?

> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/i2c/busses/i2c-designware-pcidrv.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
> index 468287922363..f1f4955f9a3f 100644
> --- a/drivers/i2c/busses/i2c-designware-pcidrv.c
> +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
> @@ -300,6 +300,7 @@ static void i2c_dw_pci_remove(struct pci_dev *pdev)
>  
>  	i2c_dw_disable(dev);
>  
> +	pm_runtime_dont_use_autosuspend(device);

If I haven't missed anything, pm_runtime_dont_use_autosuspend()
can drop the reference and trigger a suspend, which then calls
i2c_dw_runtime_suspend() and eventually i2c_dw_disable() for the
second time.

If this is correct, pm_runtime_dont_use_autosuspend() should be
moved towards the end, followed by i2c_dw_disable(), which would
then need to become the final cleanup step.

Intel folks need to verify the order anyway.

Thanks,
Andi

>  	pm_runtime_forbid(device);
>  	pm_runtime_get_noresume(device);
>  
> -- 
> 2.43.0
>