path: root/arch/powerpc/platforms/powermac/feature.c
diff options
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-02-07 14:29:43 +1100
committerPaul Mackerras <paulus@samba.org>2008-02-08 19:52:35 +1100
commit592a607bbc053bc6f614a0e619326009f4b3829e (patch)
treef6deedbe40c525c8fe088e08f620cd76cb865591 /arch/powerpc/platforms/powermac/feature.c
parenta4ffc0a0b240a29cbe489f6db9dae112a49ef1c1 (diff)
[POWERPC] Disable G5 NAP mode during SMU commands on U3
It appears that with the U3 northbridge, if the processor is in NAP mode the whole time while waiting for an SMU command to complete, then the SMU will fail. It could be related to the weird backward mechanism the SMU uses to get to system memory via i2c to the northbridge that doesn't operate properly when the said bridge is in napping along with the CPU. That is on U3 at least, U4 doesn't seem to be affected. This didn't show before NO_HZ as the timer wakeup was enough to make it work it seems, but that is no longer the case. This fixes it by disabling NAP mode on those machines while an SMU command is in flight. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/platforms/powermac/feature.c')
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powermac/feature.c b/arch/powerpc/platforms/powermac/feature.c
index ba931be2175c..5169ecc37123 100644
--- a/arch/powerpc/platforms/powermac/feature.c
+++ b/arch/powerpc/platforms/powermac/feature.c
@@ -2565,6 +2565,8 @@ static void __init probe_uninorth(void)
/* Locate core99 Uni-N */
uninorth_node = of_find_node_by_name(NULL, "uni-n");
+ uninorth_maj = 1;
/* Locate G5 u3 */
if (uninorth_node == NULL) {
uninorth_node = of_find_node_by_name(NULL, "u3");
@@ -2575,8 +2577,10 @@ static void __init probe_uninorth(void)
uninorth_node = of_find_node_by_name(NULL, "u4");
uninorth_maj = 4;
- if (uninorth_node == NULL)
+ if (uninorth_node == NULL) {
+ uninorth_maj = 0;
+ }
addrp = of_get_property(uninorth_node, "reg", NULL);
if (addrp == NULL)
@@ -3029,3 +3033,8 @@ void pmac_resume_agp_for_card(struct pci_dev *dev)
+int pmac_get_uninorth_variant(void)
+ return uninorth_maj;

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