Hi All,
Please help to review this RFC patch, if you are ok with it. I'll separte them
into
2 and repost.
1. make the boot_hpet_disable extern
2. add quirk for baytrail HPET.
thanks!
- Feng
>From 4b8c370649f1d2b320aa46a005b8b61eb59a539e Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.t...@intel.com>
Date: Fri, 18 Apr 2014 15:43:22 +0800
Subject: [PATCH] x86, hpet: Add quirk to disable HPET for baytrail platform
HPET on current baytrail platform has accuracy problem to be used as
reliable clocksource/clockevent, so add a early quirk to disable it.
Signed-off-by: Feng Tang <feng.t...@intel.com>
---
arch/x86/include/asm/hpet.h | 1 +
arch/x86/kernel/early-quirks.c | 14 ++++++++++++++
arch/x86/kernel/hpet.c | 2 +-
3 files changed, 16 insertions(+), 1 deletions(-)
diff --git a/arch/x86/include/asm/hpet.h b/arch/x86/include/asm/hpet.h
index b18df57..36f7125 100644
--- a/arch/x86/include/asm/hpet.h
+++ b/arch/x86/include/asm/hpet.h
@@ -63,6 +63,7 @@
/* hpet memory map physical address */
extern unsigned long hpet_address;
extern unsigned long force_hpet_address;
+extern int boot_hpet_disable;
extern u8 hpet_blockid;
extern int hpet_force_user;
extern u8 hpet_msi_disable;
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index bc4a088..1e5f6bc 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -17,6 +17,7 @@
#include <asm/dma.h>
#include <asm/io_apic.h>
#include <asm/apic.h>
+#include <asm/hpet.h>
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/irq_remapping.h>
@@ -380,6 +381,13 @@ static void __init intel_graphics_stolen(int num, int
slot, int func)
}
}
+static void __init force_disable_hpet(int num, int slot, int func)
+{
+ boot_hpet_disable = 1;
+ pr_info("Will Disable HPET for this platform\n");
+}
+
+
#define QFLAG_APPLY_ONCE 0x1
#define QFLAG_APPLIED 0x2
#define QFLAG_DONE (QFLAG_APPLY_ONCE|QFLAG_APPLIED)
@@ -417,6 +425,12 @@ static struct chipset early_qrk[] __initdata = {
PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check },
{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID, PCI_CLASS_DISPLAY_VGA, PCI_ANY_ID,
QFLAG_APPLY_ONCE, intel_graphics_stolen },
+ /*
+ * HPET on current version of Baytrail platform has accuracy
+ * problem, disable it for now
+ */
+ { PCI_VENDOR_ID_INTEL, 0x0f00,
+ PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet},
{}
};
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index da85a8e..913e207 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -88,7 +88,7 @@ static inline void hpet_clear_mapping(void)
/*
* HPET command line enable / disable
*/
-static int boot_hpet_disable;
+int boot_hpet_disable;
int hpet_force_user;
static int hpet_verbose;
--
1.7.0.4
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