Patchwork [1/2] powerpc/5200: Fix size to request_mem_region() call

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Submitter Grant Likely
Date Jan. 18, 2013, 1:39 a.m.
Message ID <1358473200-17886-1-git-send-email-grant.likely@secretlab.ca>
Download mbox | patch
Permalink /patch/213427/
State Not Applicable
Delegated to: Kumar Gala
Headers show

Comments

Grant Likely - Jan. 18, 2013, 1:39 a.m.
The Bestcomm driver requests a memory region larger than the one
described in the device tree. This is due to an extra undocumented field
in the bestcomm register structure. This hasn't been a problem up to
now, but there is a patch pending to make the DT platform_bus support
code use platform_device_add() which tightens the rules and provides
extra checks for drivers to stay within the specified register regions.

Alternately, I could have removed the extra field from the structure,
but I'm not sure if it is still needed for resume to work. Better be
safe and leave it in.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Anatolij Gustschin <agust@denx.de>
---
 arch/powerpc/sysdev/bestcomm/bestcomm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Anatolij Gustschin - Jan. 22, 2013, 9:10 p.m.
Hi Grant,

On Fri, 18 Jan 2013 01:39:59 +0000
Grant Likely <grant.likely@secretlab.ca> wrote:

> The Bestcomm driver requests a memory region larger than the one
> described in the device tree. This is due to an extra undocumented field
> in the bestcomm register structure. This hasn't been a problem up to
> now, but there is a patch pending to make the DT platform_bus support
> code use platform_device_add() which tightens the rules and provides
> extra checks for drivers to stay within the specified register regions.
> 
> Alternately, I could have removed the extra field from the structure,
> but I'm not sure if it is still needed for resume to work. Better be
> safe and leave it in.
> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Anatolij Gustschin <agust@denx.de>
> ---
>  arch/powerpc/sysdev/bestcomm/bestcomm.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

There is a patch moving this driver to drivers/dma,

http://patchwork.ozlabs.org/patch/191153/

I've applied it to my 5xxx next branch.

> diff --git a/arch/powerpc/sysdev/bestcomm/bestcomm.c b/arch/powerpc/sysdev/bestcomm/bestcomm.c
> index d913063..81c3314 100644
> --- a/arch/powerpc/sysdev/bestcomm/bestcomm.c
> +++ b/arch/powerpc/sysdev/bestcomm/bestcomm.c
> @@ -414,7 +414,7 @@ static int mpc52xx_bcom_probe(struct platform_device *op)
>  		goto error_sramclean;
>  	}
>  
> -	if (!request_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma),
> +	if (!request_mem_region(res_bcom.start, resource_size(&res_bcom),
>  				DRIVER_NAME)) {
>  		printk(KERN_ERR DRIVER_NAME ": "
>  			"Can't request registers region\n");

similar change is needed for release_mem_region() in error path
and in driver's remove() function.

Thanks,

Anatolij

Patch

diff --git a/arch/powerpc/sysdev/bestcomm/bestcomm.c b/arch/powerpc/sysdev/bestcomm/bestcomm.c
index d913063..81c3314 100644
--- a/arch/powerpc/sysdev/bestcomm/bestcomm.c
+++ b/arch/powerpc/sysdev/bestcomm/bestcomm.c
@@ -414,7 +414,7 @@  static int mpc52xx_bcom_probe(struct platform_device *op)
 		goto error_sramclean;
 	}
 
-	if (!request_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma),
+	if (!request_mem_region(res_bcom.start, resource_size(&res_bcom),
 				DRIVER_NAME)) {
 		printk(KERN_ERR DRIVER_NAME ": "
 			"Can't request registers region\n");