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[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>
This commit is contained in:
Benjamin Herrenschmidt 2005-05-23 10:03:52 +10:00 committed by Linus Torvalds
parent b5c44c2147
commit 1263cc67c0
2 changed files with 48 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
arch/ppc64/kernel/prom_init.c
View File

@ -1750,7 +1750,44 @@ static void __init flatten_device_tree(void)
prom_printf("Device tree struct 0x%x -> 0x%x\n",
RELOC(dt_struct_start), RELOC(dt_struct_end));
}
}
static void __init fixup_device_tree(void)
{
unsigned long offset = reloc_offset();
phandle u3, i2c, mpic;
u32 u3_rev;
u32 interrupts[2];
u32 parent;
/* Some G5s have a missing interrupt definition, fix it up here */
u3 = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000"));
if ((long)u3 <= 0)
return;
i2c = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000/i2c@f8001000"));
if ((long)i2c <= 0)
return;
mpic = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000/mpic@f8040000"));
if ((long)mpic <= 0)
return;
/* check if proper rev of u3 */
if (prom_getprop(u3, "device-rev", &u3_rev, sizeof(u3_rev)) <= 0)
return;
if (u3_rev != 0x35)
return;
/* does it need fixup ? */
if (prom_getproplen(i2c, "interrupts") > 0)
return;
/* interrupt on this revision of u3 is number 0 and level */
interrupts[0] = 0;
interrupts[1] = 1;
prom_setprop(i2c, "interrupts", &interrupts, sizeof(interrupts));
parent = (u32)mpic;
prom_setprop(i2c, "interrupt-parent", &parent, sizeof(parent));
}
static void __init prom_find_boot_cpu(void)
{
@ -1919,6 +1956,11 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4, unsigned long
PTRRELOC(&prom_tce_alloc_end), sizeof(RELOC(prom_tce_alloc_end)));
}
/*
* Fixup any known bugs in the device-tree
*/
fixup_device_tree();
/*
* Now finally create the flattened device-tree
*/

5
drivers/i2c/busses/i2c-keywest.c
View File

@ -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;