Hi Joey, Check kernel/kgdb.c. That code should be there. It was moved to kernel/debug/debug_core.c in kernel 2.6.35: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=c433820971ffa854feda6adc17f5f24201354f11 Best Regards Michal Frynas -----Original Message----- From: joey.jiaojg [mailto:joey.jiaojg@xxxxxxxxx] Sent: 28 marca 2012 03:34 To: Frynas Michal K Subject: Re: Disable modem's watchdog when kernel debugging with KGDB Hi Michal, I want to try you method. But I don't have kernel/debug/debug_core.c in kernel 2.6.32 from caf. On 2012年03月23日 17:56, Michal.K.Frynas@xxxxxxxxx wrote: > Hi, > > I was trying to launch KGDB kernel debugging on MSM 8255 platform. > It works now but I needed to apply a few patches. Among other things > I needed to neutralized AMSS' watchdog for the time the linux kernel > spends on breakpoint. Please have a look at the patch below with code > of a driver controlling modem's watchdog. > > It might be useful for everyone willing to debug the kernel > on Qualcomm's platform. > > For it to work there's another patch needed. The patch I've posted > on KGDB mailing list: http://sourceforge.net/mailarchive/message.php?msg_id=28955742 > It adds hooks for architecture specific pre and post breakpoint > handlers and invocations before and after the breakpoint. > > Best Regards > Michal Frynas > > > From 077f79c950f15ba0f4af08381b16d093a17c3354 Mon Sep 17 00:00:00 2001 > From: Michal Frynas<michal.frynas@xxxxxxxxx> > Date: Wed, 7 Mar 2012 12:59:28 +0100 > Subject: [PATCH] KGDB: modem watchdog immunization against kernel stopping > > On Qualcomm's MSM 8255 platform there are two processors running > simultaneously and synchronizing constantly with each other. > The ARM11 CPU executes Linux code while the ARM9 executes modem code. > > While debugging Linux code and stopping kernel on a breakpoint > the synchronization breaks causing modem CPU to trigger hard reset. > To avoid this modem_watchdog_control driver registers pre_exception > handler where it instructs modem watchdog to ignore timing issues > from Linux side. That handler is invoked every time the kernel enters > breakpoint and then when leaving breakpoint post_exception handler is > called restoring modem watchdog to its default behavior. > > Change-Id: I8ab73b1c8edcec1fe89b0d2f2dfbd03f0a617f57 > Signed-off-by: Michal Frynas<michal.k.frynas@xxxxxxxxx> > --- > arch/arm/mach-msm/Makefile | 2 + > arch/arm/mach-msm/modem_watchdog_control.c | 35 +++++++++++++++++++ > arch/arm/mach-msm/modem_watchdog_control.h | 50 ++++++++++++++++++++++++++++ > 3 files changed, 87 insertions(+), 0 deletions(-) > create mode 100644 arch/arm/mach-msm/modem_watchdog_control.c > create mode 100644 arch/arm/mach-msm/modem_watchdog_control.h > > diff --git a/arch/arm/mach-msm/Makefile b/arch/arm/mach-msm/Makefile > index 7ce284d..9984467 100755 > --- a/arch/arm/mach-msm/Makefile > +++ b/arch/arm/mach-msm/Makefile > @@ -208,3 +208,5 @@ endif > obj-$(CONFIG_PMIC_TIME) += pmic_time.o > > obj-$(CONFIG_SEMC_MOGAMI_FELICA_SUPPORT) += semc_mogami_felica.o > + > +obj-$(CONFIG_KGDB) += modem_watchdog_control.o > diff --git a/arch/arm/mach-msm/modem_watchdog_control.c b/arch/arm/mach-msm/modem_watchdog_control.c > new file mode 100644 > index 0000000..d64ae7e > --- /dev/null > +++ b/arch/arm/mach-msm/modem_watchdog_control.c > @@ -0,0 +1,35 @@ > +#include<proc_comm.h> > +#include<modem_watchdog_control.h> > + > + > +static int modem_watchdog_state; > + > +void modem_watchdog_disable(void) > +{ > + pr_info("kgdb: disabling modem watchdog on breakpoint\n"); > + modem_watchdog_state = DOG_HALT_MONITORING; > + msm_proc_comm(PCOM_SET_SW_WATCHDOG_STATE,&modem_watchdog_state, 0); > +} > + > +void modem_watchdog_enable(void) > +{ > + pr_info("kgdb: reenabling modem watchdog\n"); > + modem_watchdog_state = DOG_DEFAULT_STATE; > + msm_proc_comm(PCOM_SET_SW_WATCHDOG_STATE,&modem_watchdog_state, 0); > +} > + > +int get_modem_watchdog_state(void) > +{ > + return modem_watchdog_state; > +} > + > +static int __init modem_watchdog_control_init(void) > +{ > + pr_info("kgdb: initializing modem watchdog control module\n"); > + arch_kgdb_ops.pre_exception = modem_watchdog_disable; > + arch_kgdb_ops.post_exception = modem_watchdog_enable; > + > + return 0; > +} > + > +late_initcall(modem_watchdog_control_init); > diff --git a/arch/arm/mach-msm/modem_watchdog_control.h b/arch/arm/mach-msm/modem_watchdog_control.h > new file mode 100644 > index 0000000..a42a350 > --- /dev/null > +++ b/arch/arm/mach-msm/modem_watchdog_control.h > @@ -0,0 +1,50 @@ > +#ifndef MODEM_WATCHDOG_CONTROL_H_ > +#define MODEM_WATCHDOG_CONTROL_H_ > + > +#include<linux/kgdb.h> > + > +/*---------------------------------------------------------------------------- > + Bits indicating watch dog state as set by remote processors > + Copied from AMSS source codes: > + amss/AMSS/products/7x30/core/debugtools/task/src/dog.c > +----------------------------------------------------------------------------*/ > + > +/* > + * Remote proc is requesting dog task to resume its default state > + */ > +#define DOG_DEFAULT_STATE 0x00000000 > + > +/* > + * Remote proc is requesting dog monitoring to be halted/enabled > + */ > +#define DOG_HALT_MONITORING 0x00000001 > + > +/* Remote proc is requesting dog task to setup/clear conditions for > + * entering modem halt state (timer based) > + */ > +#define DOG_HALT_MODEM 0x00000002 > + > +/* > + * Needed for pre_breakpoint and post_breakpoing hooks. > + */ > +extern struct kgdb_arch arch_kgdb_ops; > + > +/* > + * Sends DOG_HALT_MONITORING value to modem site causing the modem watchdog > + * ignoring tasks timeouts while still kicking the hardware watchdog. > + */ > +extern void modem_watchdog_disable(void); > + > +/* > + * Sends DOG_DEFAULT_STATE value to modem site causing the modem watchdog > + * to resume its default tasks processing. > + */ > +extern void modem_watchdog_enable(void); > + > +/* > + * Returns current status of modem watchdog. > + */ > +extern int get_modem_watchdog_state(void); > + > + > +#endif /* MODEM_WATCHDOG_CONTROL_H_ */ ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
