[PATCH] ARM: dma-mapping: Use %zu for printing a size_t variable

[PATCH] ARM: dma-mapping: Use %zu for printing a size_t variable

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam@nxp.com>

According to Documentation/printk-formats.txt when printing
a size_t variable we should use %zu or %zx format specifiers.

As we are printing a memory size value, we should better use %zu
in this case.

Reported-by: Frank Mori Hess <fmh6jj@gmail.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
---
 arch/arm/mm/dma-mapping.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 654f202a..5bcf71b 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -436,7 +436,7 @@ static int __init atomic_pool_init(void)
 		gen_pool_set_algo(atomic_pool,
 				gen_pool_first_fit_order_align,
 				(void *)PAGE_SHIFT);
-		pr_info("DMA: preallocated %zd KiB pool for atomic coherent allocations\n",
+		pr_info("DMA: preallocated %zu KiB pool for atomic coherent allocations\n",
 		       atomic_pool_size / 1024);
 		return 0;
 	}
@@ -445,7 +445,7 @@ destroy_genpool:
 	gen_pool_destroy(atomic_pool);
 	atomic_pool = NULL;
 out:
-	pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent allocation\n",
+	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 	       atomic_pool_size / 1024);
 	return -ENOMEM;
 }
-- 
1.9.1

[PATCH] ARM: dma-mapping: Use %zu for printing a size_t variable

[Matthias Brugger]

On 07/17/2016 02:10 AM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@nxp.com>
>
> According to Documentation/printk-formats.txt when printing
> a size_t variable we should use %zu or %zx format specifiers.
>
> As we are printing a memory size value, we should better use %zu
> in this case.
>
> Reported-by: Frank Mori Hess <fmh6jj@gmail.com>
> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
> ---
>  arch/arm/mm/dma-mapping.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 654f202a..5bcf71b 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -436,7 +436,7 @@ static int __init atomic_pool_init(void)
>  		gen_pool_set_algo(atomic_pool,
>  				gen_pool_first_fit_order_align,
>  				(void *)PAGE_SHIFT);
> -		pr_info("DMA: preallocated %zd KiB pool for atomic coherent allocations\n",
> +		pr_info("DMA: preallocated %zu KiB pool for atomic coherent allocations\n",
>  		       atomic_pool_size / 1024);
>  		return 0;
>  	}
> @@ -445,7 +445,7 @@ destroy_genpool:
>  	gen_pool_destroy(atomic_pool);
>  	atomic_pool = NULL;
>  out:
> -	pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent allocation\n",
> +	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",

size_t should be formated as %zu or %zx so %zx is fine here.

>  	       atomic_pool_size / 1024);
>  	return -ENOMEM;
>  }
>

[PATCH] ARM: dma-mapping: Use %zu for printing a size_t variable

[Fabio Estevam]

On Mon, Jul 18, 2016 at 1:03 PM, Matthias Brugger
<matthias.bgg@gmail.com> wrote:

> size_t should be formated as %zu or %zx so %zx is fine here.

We are printing memory size here, so we should better print it in
decimal instead of hex.

For example: let's suppose we want to print that 256kiB allocation failed.

If we use %zu:
DMA: failed to allocate 256KiB pool for atomic coherent allocation

If we use %zx:
DMA: failed to allocate 100KiB pool for atomic coherent allocation

,which is not really what we want.

[PATCH] ARM: dma-mapping: Use %zu for printing a size_t variable

[Russell King - ARM Linux]

On Mon, Jul 18, 2016 at 06:03:05PM +0200, Matthias Brugger wrote:
> 
> 
> On 07/17/2016 02:10 AM, Fabio Estevam wrote:
> >-	pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent allocation\n",
> >+	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
> 
> size_t should be formated as %zu or %zx so %zx is fine here.

However, when it prints:

DMA: failed to allocate 100 KiB pool for atomic coherent allocation

how are you going to interpret it if you don't know the format string?

This change is exactly the right thing to do here.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

[PATCH] ARM: dma-mapping: Use %zu for printing a size_t variable

[Matthias Brugger]

On 07/18/2016 06:11 PM, Fabio Estevam wrote:
> On Mon, Jul 18, 2016 at 1:03 PM, Matthias Brugger
> <matthias.bgg@gmail.com> wrote:
>
>> size_t should be formated as %zu or %zx so %zx is fine here.
>
> We are printing memory size here, so we should better print it in
> decimal instead of hex.
>
> For example: let's suppose we want to print that 256kiB allocation failed.
>
> If we use %zu:
> DMA: failed to allocate 256KiB pool for atomic coherent allocation
>
> If we use %zx:
> DMA: failed to allocate 100KiB pool for atomic coherent allocation
>
> ,which is not really what we want.
>

Fair enough, didn't realize that.

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>