Re: Linux 2.6.18-rc6

[Olaf Hering <olaf@aepfle.de>]

On Fri, Sep 15, Doug Ledford wrote:

> On Thu, 2006-09-07 at 09:04 -0500, James Bottomley wrote:
> > On Thu, 2006-09-07 at 11:15 +0200, Olaf Hering wrote:
> > > This does not work: ahc_linux_get_signalling: f 56f6
> > > 
> > > echo $(( 0x56f6 & 0x00002 )) gives 2, and the ahc_inb is called.
> > 
> > Erm, there's something else going on then:  An ultra 2 card has to have
> > this register.  It's used to signal mode changes in
> > ahc_handle_scsiint().  The piece of code in there will trigger and read
> > this register for any ultra 2 + controller every time there's an error
> > (just to see if the bus mode changed).
> 
> Sorry for my belated response, but this usually happens when you access
> an aic chipset too soon after a chip reset.  Try putting a delay before
> whatever access is causing this to see if it make s difference.  Common
> problems include after a chip reset, touching any register will cause
> the card to reset, etc.

As pointed out in private mail, this patch fixes the machine check for
me. Thanks Doug.

Maybe the AHC_ULTRA2 feature check is needed as well for other cards.

---
 drivers/scsi/aic7xxx/aic7xxx_osm.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

Index: linux-2.6.18-rc7/drivers/scsi/aic7xxx/aic7xxx_osm.c
===================================================================
--- linux-2.6.18-rc7.orig/drivers/scsi/aic7xxx/aic7xxx_osm.c
+++ linux-2.6.18-rc7/drivers/scsi/aic7xxx/aic7xxx_osm.c
@@ -2539,7 +2539,14 @@ static void ahc_linux_set_iu(struct scsi
 static void ahc_linux_get_signalling(struct Scsi_Host *shost)
 {
 	struct ahc_softc *ahc = *(struct ahc_softc **)shost->hostdata;
-	u8 mode = ahc_inb(ahc, SBLKCTL);
+	unsigned long flags;
+	u8 mode;
+
+	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;