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| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2008-09-05 14:05:33 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-09-06 15:33:31 +0200 |
| commit | dfdf748a61a21b7397b9f57c83de722de71dc56a (patch) | |
| tree | 78fce25782a3a313a4d8db4464a849e66cc77fa8 /drivers/clocksource/acpi_pm.c | |
| parent | 4ff4b9e19a80b73959ebeb28d1df40176686f0a8 (diff) | |
| download | blackbird-op-linux-dfdf748a61a21b7397b9f57c83de722de71dc56a.tar.gz blackbird-op-linux-dfdf748a61a21b7397b9f57c83de722de71dc56a.zip | |
clocksource, acpi_pm.c: use proper read function also in errata mode
On all hardware (some Intel ICH4, PIIX4 and PIIX4E chipsets) affected by a
hardware errata there's about a 4.2% chance that initialization of the
ACPI PMTMR fails. On those chipsets, we need to read out the timer value
at least three times to get a correct result, for every once in a while
(i.e. within a 3 ns window every 69.8 ns) the read returns a bogus
result. During normal operation we work around this issue, but during
initialization reading a bogus value may lead to -EINVAL even though the
hardware is usable.
Thanks to Andreas Mohr for spotting this issue.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/clocksource/acpi_pm.c')
| -rw-r--r-- | drivers/clocksource/acpi_pm.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c index 5ca1d80de182..860d033bc74f 100644 --- a/drivers/clocksource/acpi_pm.c +++ b/drivers/clocksource/acpi_pm.c @@ -151,13 +151,13 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE, */ static int verify_pmtmr_rate(void) { - u32 value1, value2; + cycle_t value1, value2; unsigned long count, delta; mach_prepare_counter(); - value1 = read_pmtmr(); + value1 = clocksource_acpi_pm.read(); mach_countup(&count); - value2 = read_pmtmr(); + value2 = clocksource_acpi_pm.read(); delta = (value2 - value1) & ACPI_PM_MASK; /* Check that the PMTMR delta is within 5% of what we expect */ @@ -177,7 +177,7 @@ static int verify_pmtmr_rate(void) static int __init init_acpi_pm_clocksource(void) { - u32 value1, value2; + cycle_t value1, value2; unsigned int i; if (!pmtmr_ioport) @@ -187,9 +187,9 @@ static int __init init_acpi_pm_clocksource(void) clocksource_acpi_pm.shift); /* "verify" this timing source: */ - value1 = read_pmtmr(); + value1 = clocksource_acpi_pm.read(); for (i = 0; i < 10000; i++) { - value2 = read_pmtmr(); + value2 = clocksource_acpi_pm.read(); if (value2 == value1) continue; if (value2 > value1) @@ -197,11 +197,11 @@ static int __init init_acpi_pm_clocksource(void) if ((value2 < value1) && ((value2) < 0xFFF)) goto pm_good; printk(KERN_INFO "PM-Timer had inconsistent results:" - " 0x%#x, 0x%#x - aborting.\n", value1, value2); + " 0x%#llx, 0x%#llx - aborting.\n", value1, value2); return -EINVAL; } printk(KERN_INFO "PM-Timer had no reasonable result:" - " 0x%#x - aborting.\n", value1); + " 0x%#llx - aborting.\n", value1); return -ENODEV; pm_good: |
