[patch] rapidio: use resource_size()

[patch] rapidio: use resource_size()

[Dan Carpenter]

The size calculation is done incorrectly here because it should include
both the start and end (end - start + 1).  It's easiest to just use
resource_size() which does the right thing.

I was worried there was something non-standard going on because the
printk() subtracts "end - 1", but the rest of the file uses the normal
resource size calculations.  This function is only called from
fsl_rio_setup() in arch/powerpc/sysdev/fsl_rio.c and the calculation
there is also:
	port->iores.start = law_start;
	port->iores.end = law_start + law_size - 1;
So I think this is the correct fix.

Signed-off-by: Dan Carpenter <error27@gmail.com>
---
Compile tested only.

diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index 68cf0c9..7b5080c 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -1159,11 +1159,11 @@ int __devinit rio_init_mports(void)
 
 	list_for_each_entry(port, &rio_mports, node) {
 		if (!request_mem_region(port->iores.start,
-					port->iores.end - port->iores.start,
+					resource_size(&port->iores),
 					port->name)) {
 			printk(KERN_ERR
 			       "RIO: Error requesting master port region 0x%016llx-0x%016llx\n",
-			       (u64)port->iores.start, (u64)port->iores.end - 1);
+			       (u64)port->iores.start, (u64)port->iores.end);
 			rc = -ENOMEM;
 			goto out;
 		}

Re: [patch] rapidio: use resource_size()

[Li Yang]

On Thu, Oct 28, 2010 at 10:06 PM, Dan Carpenter <error27@gmail.com> wrote:
> The size calculation is done incorrectly here because it should include
> both the start and end (end - start + 1).  It's easiest to just use
> resource_size() which does the right thing.
>
> I was worried there was something non-standard going on because the
> printk() subtracts "end - 1", but the rest of the file uses the normal
> resource size calculations.  This function is only called from

Looks like a non-standard hack to make the res.end equal to actual end
+ 1.  I have updated the fsl_rio.c to use standard resource semantic,
so the hack was long broken.

> fsl_rio_setup() in arch/powerpc/sysdev/fsl_rio.c and the calculation
> there is also:
>        port->iores.start = law_start;
>        port->iores.end = law_start + law_size - 1;
> So I think this is the correct fix.
>
> Signed-off-by: Dan Carpenter <error27@gmail.com>

Acked-by: Li Yang <leoli@freescale.com>

> ---
> Compile tested only.
>
> diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
> index 68cf0c9..7b5080c 100644
> --- a/drivers/rapidio/rio.c
> +++ b/drivers/rapidio/rio.c
> @@ -1159,11 +1159,11 @@ int __devinit rio_init_mports(void)
>
>        list_for_each_entry(port, &rio_mports, node) {
>                if (!request_mem_region(port->iores.start,
> -                                       port->iores.end - port->iores.start,
> +                                       resource_size(&port->iores),
>                                        port->name)) {
>                        printk(KERN_ERR
>                               "RIO: Error requesting master port region 0x%016llx-0x%016llx\n",
> -                              (u64)port->iores.start, (u64)port->iores.end - 1);
> +                              (u64)port->iores.start, (u64)port->iores.end);
>                        rc = -ENOMEM;
>                        goto out;
>                }
> --
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-- 
- Leo