On Mon, 20 Aug 2007 14:31:04 -0700
Daniel Walker <dwalker@xxxxxxxxxx> wrote:
> On Tue, 2007-08-21 at 01:10 +0400, Konstantin Baydarov wrote:
>
> It was in your original email .. Are you saying this it is not a
> problem in plain 2.6.23-rc2? I thought I read that it was a problem on
> i386 ..
>
> Daniel
>
I can reproduce bug with plain 2.6.23-rc3 i386 kernel, without RT patch,
on pentiumd.
So I fixed this issue the same way as I fixed RT kernel. The side effect
of this fix is that when kernel 2 executes both Local APIC timer and HPET
are enabled and produce timer interrupts:
root@xxxxxxxxxxxxx:~# cat /proc/interrupts
CPU0 CPU1
0: 5643 0 IO-APIC-edge timer
1: 8 0 IO-APIC-edge i8042
2: 0 0 XT-PIC-XT cascade
4: 303 181 IO-APIC-edge serial
6: 3 0 IO-APIC-edge floppy
12: 4 0 IO-APIC-edge i8042
14: 11 0 IO-APIC-edge ide0
17: 5701 16 IO-APIC-fasteoi uhci_hcd:usb3, eth0
18: 0 0 IO-APIC-fasteoi uhci_hcd:usb4
19: 0 0 IO-APIC-fasteoi uhci_hcd:usb5
20: 38 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb2
23: 3 0 IO-APIC-fasteoi libata
NMI: 0 0
LOC: 5525 5489
ERR: 0
MIS: 0
root@xxxxxxxxxxxxx:~#
IRQ0 and LOC values practically the same.
Also I didn't see this bug on linux-rt-users@xxxxxxxxxxxxxxx, maybe I should
resend it?
Patch against 2.6.23-rc3.
Signed-off-by: Konstantin Baydarov <kbaidarov@xxxxxxxxxxxxx>
arch/i386/kernel/hpet.c | 15 +++++++++++++++
arch/i386/kernel/machine_kexec.c | 5 +++++
include/asm-i386/hpet.h | 3 +++
3 files changed, 23 insertions(+)
Index: linux-2.6.23-rc3-i386/arch/i386/kernel/hpet.c
===================================================================
--- linux-2.6.23-rc3-i386.orig/arch/i386/kernel/hpet.c
+++ linux-2.6.23-rc3-i386/arch/i386/kernel/hpet.c
@@ -340,6 +340,21 @@ out_nohpet:
return 0;
}
+#ifdef CONFIG_KEXEC
+/*
+ * reenable HPET timer
+ */
+int hpet_reenable(void)
+{
+ if (!is_hpet_capable())
+ return -1;
+
+ if (hpet_clockevent.mode != CLOCK_EVT_MODE_PERIODIC)
+ hpet_set_mode(CLOCK_EVT_MODE_PERIODIC, &hpet_clockevent);
+
+ return 0;
+}
+#endif
#ifdef CONFIG_HPET_EMULATE_RTC
Index: linux-2.6.23-rc3-i386/arch/i386/kernel/machine_kexec.c
===================================================================
--- linux-2.6.23-rc3-i386.orig/arch/i386/kernel/machine_kexec.c
+++ linux-2.6.23-rc3-i386/arch/i386/kernel/machine_kexec.c
@@ -19,6 +19,7 @@
#include <asm/cpufeature.h>
#include <asm/desc.h>
#include <asm/system.h>
+#include <asm/hpet.h>
#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
static u32 kexec_pgd[1024] PAGE_ALIGNED;
@@ -109,6 +110,10 @@ NORET_TYPE void machine_kexec(struct kim
/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
+#ifdef CONFIG_HPET_TIMER
+ hpet_reenable();
+#endif
+
control_page = page_address(image->control_code_page);
memcpy(control_page, relocate_kernel, PAGE_SIZE);
Index: linux-2.6.23-rc3-i386/include/asm-i386/hpet.h
===================================================================
--- linux-2.6.23-rc3-i386.orig/include/asm-i386/hpet.h
+++ linux-2.6.23-rc3-i386/include/asm-i386/hpet.h
@@ -66,6 +66,9 @@
extern unsigned long hpet_address;
extern int is_hpet_enabled(void);
extern int hpet_enable(void);
+#ifdef CONFIG_KEXEC
+extern int hpet_reenable(void);
+#endif
#ifdef CONFIG_HPET_EMULATE_RTC
-
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