From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominik Brodowski Subject: [PATCH v2 1/2] acpi_pm.c: use proper read function also in errata mode Date: Sat, 23 Aug 2008 00:22:33 +0200 Message-ID: <20080822222233.GA547@isilmar.linta.de> References: <20080810190759.GA1879@rhlx01.hs-esslingen.de> <20080818190325.GA12581@comet.dominikbrodowski.net> <20080818121924.6b61f7af.akpm@linux-foundation.org> <20080818193517.GA22097@isilmar.linta.de> <20080818124755.162f24d1.akpm@linux-foundation.org> <20080818200916.GA18209@comet.dominikbrodowski.net> <20080818201033.GB18209@comet.dominikbrodowski.net> <20080819024334.2f3e69fa.akpm@linux-foundation.org> <20080819094938.GA21126@isilmar.linta.de> <20080819025915.c34951b6.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from isilmar.linta.de ([213.133.102.198]:35024 "EHLO linta.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754492AbYHVWWg (ORCPT ); Fri, 22 Aug 2008 18:22:36 -0400 Content-Disposition: inline In-Reply-To: <20080819025915.c34951b6.akpm@linux-foundation.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Andrew Morton Cc: Andreas Mohr , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, johnstul@us.ibm.com, hirofumi@mail.parknet.co.jp, alan@lxorguk.ukuu.org.uk, arjan@infradead.org next try... From: Dominik Brodowski Date: Fri, 22 Aug 2008 23:49:21 +0200 Subject: [PATCH 1/2] 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. CC: John Stultz CC: Thomas Gleixner CC: Ingo Molnar Signed-off-by: Dominik Brodowski --- 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 5ca1d80..860d033 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: -- 1.5.2.5