Re: [PATCH v2] USB: apple-mfi-fastcharge: fix reference leak in apple_mfi_fc_set_property

[Johan Hovold <johan@kernel.org>]

On Sat, Oct 31, 2020 at 06:11:44PM +0800, Zhang Qilong wrote:
> pm_runtime_get_sync() will increment pm usage at first and it
> will resume the device later. If runtime of the device is
> active or has error(else....), resume operation will fail. 

That's not a correct description; pm_runtime_get_sync() returns positive
if the device was already active and that's not a failure (there's
nothing to resume).

Please fix up when resending.

> If
> we do not call put operation to decrease the reference, the
> result is that this device cannot enter the idle state and
> always stay busy or other non-idle state.
> 
> Fixes: 249fa8217b846 ("USB: Add driver to control USB fast charge for iOS devices")
> Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
> ---
>  drivers/usb/misc/apple-mfi-fastcharge.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/misc/apple-mfi-fastcharge.c b/drivers/usb/misc/apple-mfi-fastcharge.c
> index b403094a6b3a..9e1ad4536e36 100644
> --- a/drivers/usb/misc/apple-mfi-fastcharge.c
> +++ b/drivers/usb/misc/apple-mfi-fastcharge.c
> @@ -120,8 +120,10 @@ static int apple_mfi_fc_set_property(struct power_supply *psy,
>  	dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
>  
>  	ret = pm_runtime_get_sync(&mfi->udev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(&mfi->udev->dev);
>  		return ret;
> +	}
>  
>  	switch (psp) {
>  	case POWER_SUPPLY_PROP_CHARGE_TYPE:

Johan