[PATCH 2/2] driver: workarroud resource request that conflist with errno PTR

[Sascha Hauer]

On Tue, Jan 06, 2015 at 12:37:06PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> broken since
> 
> commit ed6e965824303255cacc1c1a195d3684caa26bce
> Author:     Sascha Hauer <s.hauer at pengutronix.de>
> resource: Let dev_request_mem_region return an error pointer
> 
> Introduce dev_request_mem_region_err_null
> 
> only used on platform like at91 where the Ressource address collision with
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> ---
>  arch/arm/mach-at91/at91sam926x_time.c |  6 +++---
>  drivers/base/driver.c                 | 31 +++++++++++++++++++++++++++++--
>  drivers/pinctrl/pinctrl-at91.c        |  6 +++---
>  drivers/serial/atmel.c                |  6 +++---
>  include/driver.h                      |  8 ++++++++
>  5 files changed, 46 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
> index 789e1ec..cc7ad2f 100644
> --- a/arch/arm/mach-at91/at91sam926x_time.c
> +++ b/arch/arm/mach-at91/at91sam926x_time.c
> @@ -89,9 +89,9 @@ static int at91_pit_probe(struct device_d *dev)
>  		return ret;
>  	}
>  
> -	pit_base = dev_request_mem_region(dev, 0);
> -	if (IS_ERR(pit_base))
> -		return PTR_ERR(pit_base);
> +	pit_base = dev_request_mem_region_err_null(dev, 0);
> +	if (!pit_base)
> +		return -ENOENT;
>  
>  	pit_rate = clk_get_rate(clk) / 16;
>  
> diff --git a/drivers/base/driver.c b/drivers/base/driver.c
> index e0125a1..2375004 100644
> --- a/drivers/base/driver.c
> +++ b/drivers/base/driver.c
> @@ -242,8 +242,8 @@ int register_driver(struct driver_d *drv)
>  }
>  EXPORT_SYMBOL(register_driver);
>  
> -struct resource *dev_get_resource(struct device_d *dev, unsigned long type,
> -				  int num)
> +static struct resource *__dev_get_resource(struct device_d *dev,
> +		unsigned long type, int num)
>  {
>  	int i, n = 0;
>  
> @@ -256,6 +256,17 @@ struct resource *dev_get_resource(struct device_d *dev, unsigned long type,
>  		}
>  	}
>  
> +	return NULL;
> +}
> +
> +struct resource *dev_get_resource(struct device_d *dev, unsigned long type,
> +				  int num)
> +{
> +	struct resource *res = __dev_get_resource(dev, type, num);
> +
> +	if (res)
> +		return res;
> +
>  	return ERR_PTR(-ENOENT);
>  }
>  
> @@ -318,6 +329,22 @@ void __iomem *dev_request_mem_region_by_name(struct device_d *dev, const char *n
>  }
>  EXPORT_SYMBOL(dev_request_mem_region_by_name);
>  
> +void __iomem *dev_request_mem_region_err_null(struct device_d *dev, int num)
> +{
> +	struct resource *res;
> +
> +	res = __dev_get_resource(dev, IORESOURCE_MEM, num);
> +	if (!res)
> +		return res;
> +
> +	res = request_iomem_region(dev_name(dev), res->start, res->end);
> +	if (IS_ERR(res))
> +		return ERR_CAST(res);

The function promises to return NULL on error, so this is wrong here.
I just sent an updated patch so that the release doesn't get delayed any
more.

Sascha


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