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authorThomas Gleixner <tglx@linutronix.de>2010-07-14 19:36:27 (GMT)
committerThomas Gleixner <tglx@linutronix.de>2010-07-15 15:10:02 (GMT)
commit08be97962bf338161325d4901642f956ce8c1adb (patch)
treea4a765845def5eb95f954bf0d41ad283883a696e /arch/x86/kernel/early-quirks.c
parent2f7989efd4398d92b8adffce2e07dd043a0895fe (diff)
x86: Force HPET readback_cmp for all ATI chipsets
commit 30a564be (x86, hpet: Restrict read back to affected ATI chipset) restricted the workaround for the HPET bug to SMX00 chipsets. This was reasonable as those were the only ones against which we ever got a bug report. Stephan Wolf reported now that this patch breaks his IXP400 based machine. Though it's confirmed to work on other IXP400 based systems. To error out on the safe side, we force the HPET readback workaround for all ATI SMbus class chipsets. Reported-by: Stephan Wolf <stephan@letzte-bankreihe.de> LKML-Reference: <alpine.LFD.2.00.1007142134140.3321@localhost.localdomain> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Stephan Wolf <stephan@letzte-bankreihe.de> Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Diffstat (limited to 'arch/x86/kernel/early-quirks.c')
-rw-r--r--arch/x86/kernel/early-quirks.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index ebdb85c..e5cc7e8 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -18,6 +18,7 @@
#include <asm/apic.h>
#include <asm/iommu.h>
#include <asm/gart.h>
+#include <asm/hpet.h>
static void __init fix_hypertransport_config(int num, int slot, int func)
{
@@ -191,6 +192,21 @@ static void __init ati_bugs_contd(int num, int slot, int func)
}
#endif
+/*
+ * Force the read back of the CMP register in hpet_next_event()
+ * to work around the problem that the CMP register write seems to be
+ * delayed. See hpet_next_event() for details.
+ *
+ * We do this on all SMBUS incarnations for now until we have more
+ * information about the affected chipsets.
+ */
+static void __init ati_hpet_bugs(int num, int slot, int func)
+{
+#ifdef CONFIG_HPET_TIMER
+ hpet_readback_cmp = 1;
+#endif
+}
+
#define QFLAG_APPLY_ONCE 0x1
#define QFLAG_APPLIED 0x2
#define QFLAG_DONE (QFLAG_APPLY_ONCE|QFLAG_APPLIED)
@@ -220,6 +236,8 @@ static struct chipset early_qrk[] __initdata = {
PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs },
{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs_contd },
+ { PCI_VENDOR_ID_ATI, PCI_ANY_ID,
+ PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_hpet_bugs },
{}
};

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