Re: [PATCH 1/1] NET: mcan: Move runtime PM enable/disable to m_can_platform

[Dan Murphy <dmurphy@ti.com>]

Patrik

On 8/25/20 5:17 AM, Patrik Flykt wrote:
> This is a preparatory patch for upcoming PCI based M_CAN devices.
> The current PM implementation would cause PCI based drivers to
> enable PM twice, once when the pci device is added and a second
> time in m_can_class_register(). This will cause 'Unbalanced
> pm_runtime_enable!' to be logged, and is a situation that should
> be avoided.
>
> Therefore, in anticipation of PCI devices, move PM enabling out
> from M_CAN class registration to its currently only user, the
> m_can_platform driver.
>
>
> Signed-off-by: Patrik Flykt <patrik.flykt@linux.intel.com>
> ---
>   drivers/net/can/m_can/m_can.c          | 6 +-----
>   drivers/net/can/m_can/m_can_platform.c | 3 +++
>   2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 02c5795b7393..2c4d74113443 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -1817,7 +1817,6 @@ int m_can_class_register(struct m_can_classdev *m_can_dev)
>   	int ret;
>   
>   	if (m_can_dev->pm_clock_support) {
> -		pm_runtime_enable(m_can_dev->dev);
>   		ret = m_can_clk_start(m_can_dev);
>   		if (ret)
>   			goto pm_runtime_fail;
> @@ -1847,11 +1846,8 @@ int m_can_class_register(struct m_can_classdev *m_can_dev)
>   clk_disable:
>   	m_can_clk_stop(m_can_dev);
>   pm_runtime_fail:
> -	if (ret) {
> -		if (m_can_dev->pm_clock_support)
> -			pm_runtime_disable(m_can_dev->dev);
> +	if (ret)
>   		free_candev(m_can_dev->net);
> -	}
>   
>   	return ret;
>   }
> diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
> index 38ea5e600fb8..1260e99b9322 100644
> --- a/drivers/net/can/m_can/m_can_platform.c
> +++ b/drivers/net/can/m_can/m_can_platform.c
> @@ -111,7 +111,10 @@ static int m_can_plat_probe(struct platform_device *pdev)
>   
>   	m_can_init_ram(mcan_class);
>   
> +	pm_runtime_enable(mcan_class->dev);
>   	ret = m_can_class_register(mcan_class);
> +	if (ret)
> +		pm_runtime_disable(mcan_class->dev);
>   
>   failed_ret:
>   	return ret;
Reviewed-by: Dan Murphy <dmurphy@ti.com>