Re: [PATCH] [v2] i2c: stm32f7: Fix runtime PM imbalance on error

[Alain Volmat]

Hi,

Reviewed-by: Alain Volmat <alain.volmat@xxxxxx>

Thanks,
Alain

On Wed, May 27, 2020 at 01:38:53AM +0000, Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> the call returns an error code. Thus a pairing decrement is needed
> on the error handling path to keep the counter balanced.
> 
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
> ---
> 
> Changelog:
> 
> v2: - Use pm_runtime_put_noidle() instead of
>       pm_runtime_put_autosuspend(). Fix 5 more
>       similar cases within this dirver.
> ---
>  drivers/i2c/busses/i2c-stm32f7.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index 330ffed011e0..822fd1f5b5ae 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -1620,8 +1620,10 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
>  	f7_msg->smbus = false;
>  
>  	ret = pm_runtime_get_sync(i2c_dev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(i2c_dev->dev);
>  		return ret;
> +	}
>  
>  	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
>  	if (ret)
> @@ -1666,8 +1668,10 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
>  	f7_msg->smbus = true;
>  
>  	ret = pm_runtime_get_sync(dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(dev);
>  		return ret;
> +	}
>  
>  	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
>  	if (ret)
> @@ -1767,8 +1771,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  		return ret;
>  
>  	ret = pm_runtime_get_sync(dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(dev);
>  		return ret;
> +	}
>  
>  	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
>  		stm32f7_i2c_enable_wakeup(i2c_dev, true);
> @@ -1837,8 +1843,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
>  	WARN_ON(!i2c_dev->slave[id]);
>  
>  	ret = pm_runtime_get_sync(i2c_dev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(i2c_dev->dev);
>  		return ret;
> +	}
>  
>  	if (id == 0) {
>  		mask = STM32F7_I2C_OAR1_OA1EN;
> @@ -2182,8 +2190,10 @@ static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
>  	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
>  
>  	ret = pm_runtime_get_sync(i2c_dev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(i2c_dev->dev);
>  		return ret;
> +	}
>  
>  	backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
>  	backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
> @@ -2204,8 +2214,10 @@ static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
>  	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
>  
>  	ret = pm_runtime_get_sync(i2c_dev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(i2c_dev->dev);
>  		return ret;
> +	}
>  
>  	cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
>  	if (cr1 & STM32F7_I2C_CR1_PE)
> -- 
> 2.17.1
>