Re: [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Kevin,

this looks fine.  Two quick comments:

On Tue, 26 Jan 2010, Kevin Hilman wrote:

> The omap_device struct contains a 'struct platform_device'.  Normally,
> converting a platform_device pointer to an omap_device pointer
> consists of simply doing a container_of(), as is done currently by the
> to_omap_device() macro.
> 
> However, if this is attempted when using platform_device that has not
> been created as part of the omap_device creation, the container_of()
> will point to a memory location before the platform_device pointer
> which will contain random data.
> 
> Therefore, we need a way to detect valid omap_device pointers.  This
> patch solves this by using the simple magic number approach.

Sounds okay; just FYI at some point in the future, it would be good for 
one of us to take a whack at converting omap_device to contain 
platform_device, the same way that platform_device contains struct device, 
etc..

> 
> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
> ---
> Changes from original version:
> - set magic value before omap_device_register()
> 
>  arch/arm/plat-omap/include/plat/omap_device.h |    2 ++
>  arch/arm/plat-omap/omap_device.c              |   16 ++++++++++++++++
>  2 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
> index 76d4917..4677ff7 100644
> --- a/arch/arm/plat-omap/include/plat/omap_device.h
> +++ b/arch/arm/plat-omap/include/plat/omap_device.h
> @@ -62,6 +62,7 @@
>   *
>   */
>  struct omap_device {
> +	u32                             magic;
>  	struct platform_device		pdev;
>  	struct omap_hwmod		**hwmods;
>  	struct omap_device_pm_latency	*pm_lats;
> @@ -81,6 +82,7 @@ int omap_device_shutdown(struct platform_device *pdev);
>  
>  /* Core code interface */
>  
> +bool omap_device_is_valid(struct omap_device *od);
>  int omap_device_count_resources(struct omap_device *od);
>  int omap_device_fill_resources(struct omap_device *od, struct resource *res);
>  
> diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
> index d8c75c8..187a08f 100644
> --- a/arch/arm/plat-omap/omap_device.c
> +++ b/arch/arm/plat-omap/omap_device.c
> @@ -100,6 +100,8 @@
>  # error Unknown OMAP device
>  #endif
>  
> +#define OMAP_DEVICE_MAGIC 0xf00dcafe
> +
>  /* Private functions */
>  
>  /**
> @@ -413,6 +415,8 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
>  	od->pm_lats = pm_lats;
>  	od->pm_lats_cnt = pm_lats_cnt;
>  
> +	od->magic = OMAP_DEVICE_MAGIC;
> +
>  	ret = omap_device_register(od);
>  	if (ret)
>  		goto odbs_exit4;
> @@ -599,6 +603,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
>  }
>  
>  /**
> + * omap_device_is_valid()

I think kerneldoc will want a short description after the function name.  
Can plug this in here during the merge process if you want...

> + * @od: struct omap_device *
> + *
> + * Return whether struct omap_device pointer @od points to a valid
> + * omap_device.
> + */
> +bool omap_device_is_valid(struct omap_device *od)
> +{
> +	return (od && od->magic == OMAP_DEVICE_MAGIC);
> +}
> +
> +/**
>   * omap_device_get_pwrdm - return the powerdomain * associated with @od
>   * @od: struct omap_device *
>   *
> -- 
> 1.6.6
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


- Paul
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Arm (vger)]     [ARM Kernel]     [ARM MSM]     [Linux Tegra]     [Linux WPAN Networking]     [Linux Wireless Networking]     [Maemo Users]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux