[RESEND PATCH] gpio_addr_flash: Fix warnings

[RESEND PATCH] gpio_addr_flash: Fix warnings

[Alan Cox]

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/mtd/maps/gpio-addr-flash.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)


diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 1ad5caf..9760e31 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -208,7 +208,7 @@ static int __devinit gpio_flash_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	state->gpio_count     = gpios->end;
-	state->gpio_addrs     = (void *)gpios->start;
+	state->gpio_addrs     = (void *)(unsigned long)gpios->start;
 	state->gpio_values    = (void *)(state + 1);
 	state->win_size       = memory->end - memory->start + 1;
 	memset(state->gpio_values, 0xff, arr_size);
@@ -220,7 +220,7 @@ static int __devinit gpio_flash_probe(struct platform_device *pdev)
 	state->map.copy_to    = gf_copy_to;
 	state->map.bankwidth  = pdata->width;
 	state->map.size       = state->win_size * (1 << state->gpio_count);
-	state->map.virt       = (void __iomem *)memory->start;
+	state->map.virt       = (void __iomem *)(unsigned long)memory->start;
 	state->map.phys       = NO_XIP;
 	state->map.map_priv_1 = (unsigned long)state;
 

Re: [RESEND PATCH] gpio_addr_flash: Fix warnings

[Mike Frysinger]

On Tue, Nov 17, 2009 at 10:46, Alan Cox wrote:
> --- a/drivers/mtd/maps/gpio-addr-flash.c
> +++ b/drivers/mtd/maps/gpio-addr-flash.c
> -       state->gpio_addrs     = (void *)gpios->start;
> +       state->gpio_addrs     = (void *)(unsigned long)gpios->start;
> -       state->map.virt       = (void __iomem *)memory->start;
> +       state->map.virt       = (void __iomem *)(unsigned long)memory->start;

on what system do you see warnings ?  start should be resource_size_t
which should be phys_addr_t which should cast fine to a void*.
-mike

Re: [RESEND PATCH] gpio_addr_flash: Fix warnings

[Alan Cox]

On Tue, 17 Nov 2009 11:50:24 -0500
Mike Frysinger <vapier.adi@gmail.com> wrote:

> On Tue, Nov 17, 2009 at 10:46, Alan Cox wrote:
> > --- a/drivers/mtd/maps/gpio-addr-flash.c
> > +++ b/drivers/mtd/maps/gpio-addr-flash.c
> > -       state->gpio_addrs     = (void *)gpios->start;
> > +       state->gpio_addrs     = (void *)(unsigned long)gpios->start;
> > -       state->map.virt       = (void __iomem *)memory->start;
> > +       state->map.virt       = (void __iomem *)(unsigned long)memory->start;
> 
> on what system do you see warnings ?  start should be resource_size_t
> which should be phys_addr_t which should cast fine to a void*.

32bit x86 shows it up because resource_size_t is a physaddr_t which is
64bit (because of PAE). Now given you don't seem likely to be using the
top bits for any real world example that looks ok but really casting a
physical address to a pointer type needs care and the compiler can't
deduce your intent there.

Re: [RESEND PATCH] gpio_addr_flash: Fix warnings

[Mike Frysinger]

On Tue, Nov 17, 2009 at 11:58, Alan Cox wrote:
> On Tue, 17 Nov 2009 11:50:24 -0500 Mike Frysinger wrote:
>> On Tue, Nov 17, 2009 at 10:46, Alan Cox wrote:
>> > --- a/drivers/mtd/maps/gpio-addr-flash.c
>> > +++ b/drivers/mtd/maps/gpio-addr-flash.c
>> > -       state->gpio_addrs     = (void *)gpios->start;
>> > +       state->gpio_addrs     = (void *)(unsigned long)gpios->start;
>> > -       state->map.virt       = (void __iomem *)memory->start;
>> > +       state->map.virt       = (void __iomem *)(unsigned long)memory->start;
>>
>> on what system do you see warnings ?  start should be resource_size_t
>> which should be phys_addr_t which should cast fine to a void*.
>
> 32bit x86 shows it up because resource_size_t is a physaddr_t which is
> 64bit (because of PAE). Now given you don't seem likely to be using the
> top bits for any real world example that looks ok but really casting a
> physical address to a pointer type needs care and the compiler can't
> deduce your intent there.

i dont think the casts will work in either case here and it's a good
thing that the code doesnt compile warning free

the gpio_addrs member is an array of gpio ids which are 32bit unsigned
values.  overlaying an array of 64bit values isnt going to produce
correct behavior.

as for the memory->start, i do need to access that directly, so that
should probably be going through ioremap_nocache() instead.

i.e. i'll have to write/test/post a patch rather than adding casts to
pretend there isnt a problem
-mike