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authorIngo Molnar <mingo@elte.hu>2010-04-08 13:36:36 +0200
committerIngo Molnar <mingo@elte.hu>2010-04-08 13:37:18 +0200
commitca7e0c612005937a4a5a75d3fed90459993de65c (patch)
treeb574fc0f0189b52ffc87ba20c418228db556faa1 /arch/x86/kernel/hpet.c
parent8141d0050d76e5695011b5ab577ec66fb51a998c (diff)
parentf5284e7635787224dda1a2bf82a4c56b1c75671f (diff)
downloadtalos-obmc-linux-ca7e0c612005937a4a5a75d3fed90459993de65c.tar.gz
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Merge branch 'linus' into perf/core
Semantic conflict: arch/x86/kernel/cpu/perf_event_intel_ds.c Merge reason: pick up latest fixes, fix the conflict Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/hpet.c')
-rw-r--r--arch/x86/kernel/hpet.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ee4fa1bfcb33..23b4ecdffa9b 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -4,6 +4,7 @@
#include <linux/sysdev.h>
#include <linux/delay.h>
#include <linux/errno.h>
+#include <linux/slab.h>
#include <linux/hpet.h>
#include <linux/init.h>
#include <linux/cpu.h>
@@ -399,9 +400,15 @@ static int hpet_next_event(unsigned long delta,
* then we might have a real hardware problem. We can not do
* much about it here, but at least alert the user/admin with
* a prominent warning.
+ * An erratum on some chipsets (ICH9,..), results in comparator read
+ * immediately following a write returning old value. Workaround
+ * for this is to read this value second time, when first
+ * read returns old value.
*/
- WARN_ONCE(hpet_readl(HPET_Tn_CMP(timer)) != cnt,
+ if (unlikely((u32)hpet_readl(HPET_Tn_CMP(timer)) != cnt)) {
+ WARN_ONCE(hpet_readl(HPET_Tn_CMP(timer)) != cnt,
KERN_WARNING "hpet: compare register read back failed.\n");
+ }
return (s32)(hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
}
@@ -1143,6 +1150,7 @@ int hpet_set_periodic_freq(unsigned long freq)
do_div(clc, freq);
clc >>= hpet_clockevent.shift;
hpet_pie_delta = clc;
+ hpet_pie_limit = 0;
}
return 1;
}
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