[PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove

[PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove

[Dima Volkovsk]

In the current implementation of tegra_nvec_remove, the pm_power_off handler
is set to NULL without checking if it is actually set to nvec_power_off. This
change ensures that pm_power_off is only reset if it was previously set to
nvec_power_off, preventing unintended side effects when removing the device.

Signed-off-by: Dima Volkovsk <s0ldw3ll@gmail.com>
---
 drivers/staging/nvec/nvec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
index 263774e6a78c..9057f061e927 100644
--- a/drivers/staging/nvec/nvec.c
+++ b/drivers/staging/nvec/nvec.c
@@ -903,8 +903,10 @@ static void tegra_nvec_remove(struct platform_device *pdev)
 	nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);
 	cancel_work_sync(&nvec->rx_work);
 	cancel_work_sync(&nvec->tx_work);
-	/* FIXME: needs check whether nvec is responsible for power off */
-	pm_power_off = NULL;
+
+	/* only reset pm_power_off if it's our handler */
+	if (pm_power_off = nvec_power_off)
+		pm_power_off = NULL;
 }
 
 #ifdef CONFIG_PM_SLEEP
-- 
2.48.1

Re: [PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove

[Greg KH]

On Sun, Feb 09, 2025 at 09:16:48PM +0100, Dima Volkovsk wrote:
> In the current implementation of tegra_nvec_remove, the pm_power_off handler
> is set to NULL without checking if it is actually set to nvec_power_off. This
> change ensures that pm_power_off is only reset if it was previously set to
> nvec_power_off, preventing unintended side effects when removing the device.
> 
> Signed-off-by: Dima Volkovsk <s0ldw3ll@gmail.com>
> ---
>  drivers/staging/nvec/nvec.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
> index 263774e6a78c..9057f061e927 100644
> --- a/drivers/staging/nvec/nvec.c
> +++ b/drivers/staging/nvec/nvec.c
> @@ -903,8 +903,10 @@ static void tegra_nvec_remove(struct platform_device *pdev)
>  	nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);
>  	cancel_work_sync(&nvec->rx_work);
>  	cancel_work_sync(&nvec->tx_work);
> -	/* FIXME: needs check whether nvec is responsible for power off */
> -	pm_power_off = NULL;
> +
> +	/* only reset pm_power_off if it's our handler */
> +	if (pm_power_off = nvec_power_off)

I don't think you tested this :(

Re: [PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove

[kernel test robot]

Hi Dima,

kernel test robot noticed the following build warnings:

[auto build test WARNING on staging/staging-testing]

url:    https://github.com/intel-lab-lkp/linux/commits/Dima-Volkovsk/Staging-nvec-Fix-pm_power_off-reset-condition-in-tegra_nvec_remove/20250210-041929
base:   staging/staging-testing
patch link:    https://lore.kernel.org/r/20250209201752.66313-1-s0ldw3ll%40gmail.com
patch subject: [PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove
config: arm-defconfig (https://download.01.org/0day-ci/archive/20250210/202502102056.z2poG8tW-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 6807164500e9920638e2ab0cdb4bf8321d24f8eb)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250210/202502102056.z2poG8tW-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502102056.z2poG8tW-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/staging/nvec/nvec.c:908:19: warning: using the result of an assignment as a condition without parentheses [-Wparentheses]
     908 |         if (pm_power_off = nvec_power_off)
         |             ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
   drivers/staging/nvec/nvec.c:908:19: note: place parentheses around the assignment to silence this warning
     908 |         if (pm_power_off = nvec_power_off)
         |                          ^               
         |             (                            )
   drivers/staging/nvec/nvec.c:908:19: note: use '==' to turn this assignment into an equality comparison
     908 |         if (pm_power_off = nvec_power_off)
         |                          ^
         |                          ==
   1 warning generated.


vim +908 drivers/staging/nvec/nvec.c

   896	
   897	static void tegra_nvec_remove(struct platform_device *pdev)
   898	{
   899		struct nvec_chip *nvec = platform_get_drvdata(pdev);
   900	
   901		nvec_toggle_global_events(nvec, false);
   902		mfd_remove_devices(nvec->dev);
   903		nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);
   904		cancel_work_sync(&nvec->rx_work);
   905		cancel_work_sync(&nvec->tx_work);
   906	
   907		/* only reset pm_power_off if it's our handler */
 > 908		if (pm_power_off = nvec_power_off)
   909			pm_power_off = NULL;
   910	}
   911	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove

[kernel test robot]

Hi Dima,

kernel test robot noticed the following build warnings:

[auto build test WARNING on staging/staging-testing]

url:    https://github.com/intel-lab-lkp/linux/commits/Dima-Volkovsk/Staging-nvec-Fix-pm_power_off-reset-condition-in-tegra_nvec_remove/20250210-041929
base:   staging/staging-testing
patch link:    https://lore.kernel.org/r/20250209201752.66313-1-s0ldw3ll%40gmail.com
patch subject: [PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove
config: arm-allmodconfig (https://download.01.org/0day-ci/archive/20250210/202502102138.1CqFj1nV-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250210/202502102138.1CqFj1nV-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502102138.1CqFj1nV-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/staging/nvec/nvec.c: In function 'tegra_nvec_remove':
>> drivers/staging/nvec/nvec.c:908:13: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
     908 |         if (pm_power_off = nvec_power_off)
         |             ^~~~~~~~~~~~


vim +908 drivers/staging/nvec/nvec.c

   896	
   897	static void tegra_nvec_remove(struct platform_device *pdev)
   898	{
   899		struct nvec_chip *nvec = platform_get_drvdata(pdev);
   900	
   901		nvec_toggle_global_events(nvec, false);
   902		mfd_remove_devices(nvec->dev);
   903		nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);
   904		cancel_work_sync(&nvec->rx_work);
   905		cancel_work_sync(&nvec->tx_work);
   906	
   907		/* only reset pm_power_off if it's our handler */
 > 908		if (pm_power_off = nvec_power_off)
   909			pm_power_off = NULL;
   910	}
   911	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] Staging: nvec: Fix pm_power_off reset condition in tegra_nvec_remove

[Dan Carpenter]

On Sun, Feb 09, 2025 at 09:16:48PM +0100, Dima Volkovsk wrote:
> In the current implementation of tegra_nvec_remove, the pm_power_off handler
> is set to NULL without checking if it is actually set to nvec_power_off. This
> change ensures that pm_power_off is only reset if it was previously set to
> nvec_power_off, preventing unintended side effects when removing the device.
> 
> Signed-off-by: Dima Volkovsk <s0ldw3ll@gmail.com>

What everyone else said and also you forgot to add a Fixes tag.

regards,
dan carpenter