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Commit 7b75b990 authored by Denis Vlasenko's avatar Denis Vlasenko Committed by James Bottomley
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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: default avatarDenis Vlasenko <vda.linux@googlemail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>

Fixed rejections and added aic7xxx code
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 02a0fa67

drivers/scsi/aic7xxx/aic79xx_inline.h

+2 −1
Original line number Diff line number Diff line
@@ -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

drivers/scsi/aic7xxx/aic7xxx_inline.h

+2 −1
Original line number Diff line number Diff line
@@ -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