From: Olaf Hering <olh@suse.de>
To: Paul Mackeras <paulus@samba.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] powerpc: enable NAP only on cpus who support it to avoid memory corruption
Date: Sat, 11 Mar 2006 22:58:40 +0100 [thread overview]
Message-ID: <20060311215840.GA22766@suse.de> (raw)
commit 51d3082fe6e55aecfa17113dbe98077c749f724c enabled NAP unconditinally
on all powermacs. Early G3 cpus can not use it, the result is memory corruption.
Only enable powersave_nap in one place: probe_motherboard()
ppc32 gets nap if the cpu supports it
ppc32 smp gets no nap
ppc64 gets nap unconditionally
---
arch/powerpc/platforms/powermac/feature.c | 8 +++++++-
arch/powerpc/platforms/powermac/setup.c | 4 ----
arch/powerpc/platforms/powermac/smp.c | 4 ----
3 files changed, 7 insertions(+), 9 deletions(-)
Index: linux-2.6.16-rc5-olh/arch/powerpc/platforms/powermac/feature.c
===================================================================
--- linux-2.6.16-rc5-olh.orig/arch/powerpc/platforms/powermac/feature.c
+++ linux-2.6.16-rc5-olh/arch/powerpc/platforms/powermac/feature.c
@@ -2513,8 +2513,11 @@ found:
/* Nap mode not supported if flush-on-lock property is present */
if (get_property(np, "flush-on-lock", NULL))
break;
+
+#ifndef CONFIG_SMP
+ /* 32 bits SMP can't NAP */
powersave_nap = 1;
- printk(KERN_INFO "Processor NAP mode on idle enabled.\n");
+#endif
break;
}
@@ -2526,6 +2529,9 @@ found:
#ifdef CONFIG_POWER4
powersave_nap = 1;
#endif
+ if (powersave_nap)
+ printk(KERN_INFO "Using native/NAP idle loop\n");
+
/* Check for "mobile" machine */
if (model && (strncmp(model, "PowerBook", 9) == 0
|| strncmp(model, "iBook", 5) == 0))
Index: linux-2.6.16-rc5-olh/arch/powerpc/platforms/powermac/setup.c
===================================================================
--- linux-2.6.16-rc5-olh.orig/arch/powerpc/platforms/powermac/setup.c
+++ linux-2.6.16-rc5-olh/arch/powerpc/platforms/powermac/setup.c
@@ -621,10 +621,6 @@ static void __init pmac_init_early(void)
/* Probe motherboard chipset */
pmac_feature_init();
- /* We can NAP */
- powersave_nap = 1;
- printk(KERN_INFO "Using native/NAP idle loop\n");
-
/* Initialize debug stuff */
udbg_scc_init(!!strstr(cmd_line, "sccdbg"));
udbg_adb_init(!!strstr(cmd_line, "btextdbg"));
Index: linux-2.6.16-rc5-olh/arch/powerpc/platforms/powermac/smp.c
===================================================================
--- linux-2.6.16-rc5-olh.orig/arch/powerpc/platforms/powermac/smp.c
+++ linux-2.6.16-rc5-olh/arch/powerpc/platforms/powermac/smp.c
@@ -739,10 +739,6 @@ static void __init smp_core99_setup(int
smp_hw_index[i] = i;
}
#endif
-
- /* 32 bits SMP can't NAP */
- if (!machine_is_compatible("MacRISC4"))
- powersave_nap = 0;
}
static int __init smp_core99_probe(void)
next reply other threads:[~2006-03-11 21:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-11 21:58 Olaf Hering [this message]
2006-03-11 23:43 ` [PATCH] powerpc: enable NAP only on cpus who support it to avoid memory corruption Benjamin Herrenschmidt
2006-03-11 23:55 ` Benjamin Herrenschmidt
2006-03-12 10:40 ` Olaf Hering
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