On Thursday, 8 of November 2007, Johannes Berg wrote: > 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> > Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > --- > I don't really care much. I can let this patch collect dust until I > actually want to implement PM_TRACE for powerpc or another architecture > but since I had it I wanted to send it out too. > > drivers/base/power/Makefile | 2 +- > kernel/power/Kconfig | 23 ++++++++++++++++++++++- > 2 files changed, 23 insertions(+), 2 deletions(-) > > --- everything.orig/drivers/base/power/Makefile 2007-11-08 12:07:09.843121635 +0100 > +++ everything/drivers/base/power/Makefile 2007-11-08 12:19:23.593081000 +0100 > @@ -1,6 +1,6 @@ > obj-y := shutdown.o > obj-$(CONFIG_PM_SLEEP) += main.o sysfs.o > -obj-$(CONFIG_PM_TRACE) += trace.o > +obj-$(CONFIG_PM_TRACE_RTC) += trace.o > > ifeq ($(CONFIG_DEBUG_DRIVER),y) > EXTRA_CFLAGS += -DDEBUG > --- everything.orig/kernel/power/Kconfig 2007-11-08 12:04:51.443081271 +0100 > +++ everything/kernel/power/Kconfig 2007-11-08 12:12:53.863072157 +0100 > @@ -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 > > > > -- "Premature optimization is the root of all evil." - Donald Knuth _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
