rfc: vsprintf and phys_addr_t and dma_addr_t via %pa (was Re: [PATCH] spi: fix spi-atmel.c printk format warnings)

[Joe Perches <joe@perches.com>]

(Adding Stepan Moskovchenko who added %pa to vsprintf)

On Fri, 2014-03-21 at 08:53 -0700, Randy Dunlap wrote:
> Fix printk format warning by using %p extension 'ad' for dma_addr_t.

Hey Randy, Stepan and everyone else as well.

One of the things I'd like to get straightened out
before too many of these dma_addr_t conversions are
done is whether or not it should be prefixed by 0x.

%pad is not a direct replacement for %08x or %016x.
It changes the output.

Right now, all phys_addr_t and dma_addr_t types emitted
using %pa[pd] are "SPECIAL", meaning these are prefixed
with "0x".

No other pointer/address types have that "0x" prefix.

I'd prefer to remove the "SPECIAL" from the %pa extension
so that the output form of pointer/address types are
consistent.

This would change several output lines already using %pa.

I don't think that's bad, but maybe others do.

Thoughts?

---
 lib/vsprintf.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 185b6d3..28fee91 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1161,18 +1161,18 @@ char *address_val(char *buf, char *end, const void *addr,
 {
 	unsigned long long num;
 
-	spec.flags |= SPECIAL | SMALL | ZEROPAD;
+	spec.flags |= SMALL | ZEROPAD;
 	spec.base = 16;
 
 	switch (fmt[1]) {
 	case 'd':
 		num = *(const dma_addr_t *)addr;
-		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
+		spec.field_width = sizeof(dma_addr_t) * 2;
 		break;
 	case 'p':
 	default:
 		num = *(const phys_addr_t *)addr;
-		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
+		spec.field_width = sizeof(phys_addr_t) * 2;
 		break;
 	}
 


> drivers/spi/spi-atmel.c:1228:3: warning: format '%x' expects argument of type 'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat]
> drivers/spi/spi-atmel.c:1228:3: warning: format '%x' expects argument of type 'unsigned int', but argument 9 has type 'dma_addr_t' [-Wformat]
> 
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: Wenyou Yang <wenyou.yang@atmel.com>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
>  drivers/spi/spi-atmel.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> I thought that a patch for this was already posted but I can't find it...
> Applies to mainline.
> 
> --- linux-next-20140321.orig/drivers/spi/spi-atmel.c
> +++ linux-next-20140321/drivers/spi/spi-atmel.c
> @@ -1226,10 +1226,10 @@ static int atmel_spi_transfer_one_messag
>  
>  	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
>  		dev_dbg(&spi->dev,
> -			"  xfer %p: len %u tx %p/%08x rx %p/%08x\n",
> +			"  xfer %p: len %u tx %p/%pad rx %p/%pad\n",
>  			xfer, xfer->len,
> -			xfer->tx_buf, xfer->tx_dma,
> -			xfer->rx_buf, xfer->rx_dma);
> +			xfer->tx_buf, &xfer->tx_dma,
> +			xfer->rx_buf, &xfer->rx_dma);
>  	}