From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> When trying to debug a suspend failure I started implementing PM_TRACE for powerpc. I then noticed that I'm debugging a suspend failure and so PM_TRACE isn't useful at all, but thought that nonetheless this could be useful in the future. Basically, to support PM_TRACE, you add a Kconfig option that selects PM_TRACE and provides the infrastructure as per the help text of PM_TRACE. Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- drivers/base/power/Makefile | 2 +- kernel/power/Kconfig | 23 ++++++++++++++++++++++- 2 files changed, 23 insertions(+), 2 deletions(-) Index: linux-2.6/drivers/base/power/Makefile =================================================================== --- linux-2.6.orig/drivers/base/power/Makefile +++ linux-2.6/drivers/base/power/Makefile @@ -1,7 +1,7 @@ obj-y := shutdown.o obj-$(CONFIG_PM) += sysfs.o obj-$(CONFIG_PM_SLEEP) += main.o -obj-$(CONFIG_PM_TRACE) += trace.o +obj-$(CONFIG_PM_TRACE_RTC) += trace.o ifeq ($(CONFIG_DEBUG_DRIVER),y) EXTRA_CFLAGS += -DDEBUG Index: linux-2.6/kernel/power/Kconfig =================================================================== --- linux-2.6.orig/kernel/power/Kconfig +++ linux-2.6/kernel/power/Kconfig @@ -44,9 +44,30 @@ config PM_VERBOSE ---help--- This option enables verbose messages from the Power Management code. +config CAN_PM_TRACE + def_bool y + depends on PM_DEBUG && PM_SLEEP && EXPERIMENTAL + config PM_TRACE + bool + help + This enables code to save the last PM event point across + reboot. The architecture needs to support this, x86 for + example does by saving things in the RTC, see below. + + The architecture specific code must provide the extern + functions from <linux/resume-trace.h> as well as the + <asm/resume-trace.h> header with a TRACE_RESUME() macro. + + The way the information is presented is architecture- + dependent, x86 will print the information during a + late_initcall. + +config PM_TRACE_RTC bool "Suspend/resume event tracing" - depends on PM_DEBUG && X86 && PM_SLEEP && EXPERIMENTAL + depends on CAN_PM_TRACE + depends on X86 + select PM_TRACE default n ---help--- This enables some cheesy code to save the last PM event point in the - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
