[PATCH] ppc64: Fix booting on latest G5 models

The latest speedbumped Apple G5 models have a "bug" in the Open Firmware
device tree that lacks the proper interrupt routing information for the
northbridge i2c controller.  Apple's driver silently falls back into a
sub-optimal "polled" mode (heh, maybe they didn't even notice the bug
because of that :), our driver didn't properly check and crashes :(

This patch fixes our driver to not crash, and adds code to the
prom_init() OF trampoline code that detects the "bug" and adds the
missing information back for this chipset revision.  This fixes booting
and thermal control on these models.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-keywest.c b/drivers/i2c/busses/i2c-keywest.c
index dd0d4c463146..867d443e7133 100644
--- a/drivers/i2c/busses/i2c-keywest.c
+++ b/drivers/i2c/busses/i2c-keywest.c
@@ -516,6 +516,11 @@ create_iface(struct device_node *np, struct device *dev)
         u32 *psteps, *prate;
         int rc;
 
+        if (np->n_intrs < 1 || np->n_addrs < 1) {
+                printk(KERN_ERR "%s: Missing interrupt or address !\n",
+                       np->full_name);
+                return -ENODEV;
+        }
         if (pmac_low_i2c_lock(np))
                 return -ENODEV;