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[SCSI] aic7xxx: fix byte I/O order in ahd_inw 

Comment says "Read high byte first as some registers increment..."
but code doesn't guarantee that, I think:
	return ((ahd_inb(ahd, port+1) << 8) | ahd_inb(ahd, port));
Compiler can reorder it.

Make the order explicit.

Signed-off-by: Denis Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

Fixed rejections and added aic7xxx code
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
Denis Vlasenko 2006-09-25 16:57:42 -07:00 committed by James Bottomley
parent 02a0fa676c
commit 7b75b990e3
2 changed files with 4 additions and 2 deletions
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3
drivers/scsi/aic7xxx/aic79xx_inline.h
View File

@ -527,7 +527,8 @@ ahd_inw(struct ahd_softc *ahd, u_int port)
* or have other side effects when the low byte is
* read.
*/
return ((ahd_inb(ahd, port+1) << 8) | ahd_inb(ahd, port));
uint16_t r = ahd_inb(ahd, port+1) << 8;
return r | ahd_inb(ahd, port);
}
static __inline void

3
drivers/scsi/aic7xxx/aic7xxx_inline.h
View File

@ -300,7 +300,8 @@ ahc_fetch_transinfo(struct ahc_softc *ahc, char channel, u_int our_id,
static __inline uint16_t
ahc_inw(struct ahc_softc *ahc, u_int port)
{
return ((ahc_inb(ahc, port+1) << 8) | ahc_inb(ahc, port));
uint16_t r = ahc_inb(ahc, port+1) << 8;
return r | ahc_inb(ahc, port);
}
static __inline void