[SCSI] aic7xxx: pause sequencer before touching SBLKCTL

Some cards need to pause the sequencer before the SBLKCTL register is
touched.  This fixes a PCI related oops seen on powerpc macs with this
card caused by trying to ascertain the bus signalling before beginning
domain validation.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/aic7xxx/aic7xxx_osm.c b/drivers/scsi/aic7xxx/aic7xxx_osm.c
index 0b3c01ac42596fd605725346e9ce954ffcd49fb8..64c8b88a429fa1d11228138babe693518db30edb 100644 (file)
--- a/drivers/scsi/aic7xxx/aic7xxx_osm.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_osm.c
@@ -2539,6 +2539,7 @@ static void ahc_linux_set_iu(struct scsi_target *starget, int iu)
 static void ahc_linux_get_signalling(struct Scsi_Host *shost)
 {
        struct ahc_softc *ahc = *(struct ahc_softc **)shost->hostdata;
+       unsigned long flags;
        u8 mode;
 
        if (!(ahc->features & AHC_ULTRA2)) {
@@ -2550,7 +2551,11 @@ static void ahc_linux_get_signalling(struct Scsi_Host *shost)
                return;
        }
 
+       ahc_lock(ahc, &flags);
+       ahc_pause(ahc);
        mode = ahc_inb(ahc, SBLKCTL);
+       ahc_unpause(ahc);
+       ahc_unlock(ahc, &flags);
 
        if (mode & ENAB40)
                spi_signalling(shost) = SPI_SIGNAL_LVD;