[PATCH] spi: fix SPI_BIT_MASK() to use correct size for 32-bit transfer mask

[PATCH] spi: fix SPI_BIT_MASK() to use correct size for 32-bit transfer mask

[Mika Westerberg]

When building a 64-bit kernel we get the following warning from the
compiler:

 drivers/spi/spi-pxa2xx.c: In function ‘pxa2xx_spi_probe’:
 drivers/spi/spi-pxa2xx.c:1152:3: warning: large integer implicitly truncated to unsigned type [-Woverflow]
   master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
   ^
This is due the fact that when the max range is specified as 32
SPI_BIT_MASK() expands to ~0UL which doesn't fit to the u32 type that the
master->bits_per_word_mask is.

Fix this by using ~0U instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 include/linux/spi/spi.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 28e440b..c920c2f 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -309,7 +309,7 @@ struct spi_master {
 	/* bitmask of supported bits_per_word for transfers */
 	u32			bits_per_word_mask;
 #define SPI_BPW_MASK(bits) BIT((bits) - 1)
-#define SPI_BIT_MASK(bits) (((bits) == 32) ? ~0UL : (BIT(bits) - 1))
+#define SPI_BIT_MASK(bits) (((bits) == 32) ? ~0U : (BIT(bits) - 1))
 #define SPI_BPW_RANGE_MASK(min, max) (SPI_BIT_MASK(max) - SPI_BIT_MASK(min - 1))
 
 	/* other constraints relevant to this driver */
-- 
1.8.4.rc2

Re: [PATCH] spi: fix SPI_BIT_MASK() to use correct size for 32-bit transfer mask

[Stephen Warren]

On 08/20/2013 06:15 AM, Mika Westerberg wrote:
> When building a 64-bit kernel we get the following warning from the
> compiler:
> 
>  drivers/spi/spi-pxa2xx.c: In function ‘pxa2xx_spi_probe’:
>  drivers/spi/spi-pxa2xx.c:1152:3: warning: large integer implicitly truncated to unsigned type [-Woverflow]
>    master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
>    ^
> This is due the fact that when the max range is specified as 32
> SPI_BIT_MASK() expands to ~0UL which doesn't fit to the u32 type that the
> master->bits_per_word_mask is.
> 
> Fix this by using ~0U instead.

The same patch is already in next-20130819 at least, as:
b6aa23c spi: fix SPI_BIT_MASK so it always fits into 32-bits

Re: [PATCH] spi: fix SPI_BIT_MASK() to use correct size for 32-bit transfer mask

[Mika Westerberg]

On Tue, Aug 20, 2013 at 10:37:34AM -0600, Stephen Warren wrote:
> On 08/20/2013 06:15 AM, Mika Westerberg wrote:
> > When building a 64-bit kernel we get the following warning from the
> > compiler:
> > 
> >  drivers/spi/spi-pxa2xx.c: In function ‘pxa2xx_spi_probe’:
> >  drivers/spi/spi-pxa2xx.c:1152:3: warning: large integer implicitly truncated to unsigned type [-Woverflow]
> >    master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
> >    ^
> > This is due the fact that when the max range is specified as 32
> > SPI_BIT_MASK() expands to ~0UL which doesn't fit to the u32 type that the
> > master->bits_per_word_mask is.
> > 
> > Fix this by using ~0U instead.
> 
> The same patch is already in next-20130819 at least, as:
> b6aa23c spi: fix SPI_BIT_MASK so it always fits into 32-bits

Cool :) Thanks for letting me know.