Re: [PATCH v8] can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 08/20/2012 10:45 AM, AnilKumar Ch wrote:
> Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM
> APIs control clocks for C_CAN/D_CAN IP and prevent access to the
> register of C_CAN/D_CAN IP when clock is turned off.
> 
> Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
> ---
> This patch has been tested on AM335X EVM. Due to lack of hardware
> I am not able to test c_can functionality. I appreciate if anyone
> can test c_can functionality with this patch.
> 
> This patch is based on "can-next/master" 
> 
> Changes from v7:
> 	- Incorporated Marc's commets on v7
> 	  * changed device pointer to c_can_priv pointer

looks good.

[...]

> --- a/drivers/net/can/c_can/c_can_platform.c
> +++ b/drivers/net/can/c_can/c_can_platform.c
> @@ -32,6 +32,7 @@
>  #include <linux/clk.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
>  
>  #include <linux/can/dev.h>
>  
> @@ -177,8 +178,11 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
>  		goto exit_free_device;
                     ^^^^^^^^^^^^^^^^
>  	}
>  
> +	pm_runtime_enable(&pdev->dev);
> +
>  	dev->irq = irq;
>  	priv->base = addr;
> +	priv->device = &pdev->dev;
>  	priv->can.clock.freq = clk_get_rate(clk);
>  	priv->priv = clk;
>  
> @@ -198,6 +202,7 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
>  
>  exit_free_device:
>  	platform_set_drvdata(pdev, NULL);
> +	pm_runtime_disable(&pdev->dev);

I think this will end up in a NULL pointer deferf.

>  	free_c_can_dev(dev);
>  exit_iounmap:
>  	iounmap(addr);
> @@ -226,6 +231,7 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev)
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	release_mem_region(mem->start, resource_size(mem));
>  
> +	pm_runtime_disable(&pdev->dev);
>  	clk_put(priv->priv);
>  
>  	return 0;
> 

Marc

-- 
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