Re: [PATCH 4/5] staging: nvec: fix pm_power_off teardown in tegra_nvec_remove()

[Dan Carpenter <error27@gmail.com>]

On Sun, Apr 12, 2026 at 10:51:17PM +0200, Alexandru Hossu wrote:
> The remove() function unconditionally sets pm_power_off to NULL regardless
> of whether this driver instance was the one that set it. There is even a
> FIXME comment acknowledging this. Additionally, nvec_power_handle is never
> cleared on removal, leaving a dangling pointer to freed device data.
> 
> Fix both issues: check that pm_power_off still points to nvec_power_off
> before clearing it, and also clear nvec_power_handle at the same time.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@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 75877038847f..9fe9b7a3491d 100644
> --- a/drivers/staging/nvec/nvec.c
> +++ b/drivers/staging/nvec/nvec.c
> @@ -907,8 +907,10 @@ 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;
> +	if (pm_power_off == nvec_power_off) {
> +		pm_power_off = NULL;
> +		nvec_power_handle = NULL;
> +	}

Linux power off handling is a known mess...

I wonder why the original added a comment instead of a test?  To me
checking for if if (pm_power_off == nvec_power_off) makes sense and I
can't see how it would hurt anything.

At this point, we're unloading the driver so nvec_power_handle is
about to be freed.  Is there any benefit to setting it to NULL?

regards,
dan carpenter