Re: ftraced and suspend to ram

[Marcin Slusarz <marcin.slusarz@gmail.com>]

On Fri, Aug 22, 2008 at 06:39:34PM +0200, Rafael J. Wysocki wrote:
> On Friday, 22 of August 2008, Marcin Slusarz wrote:
> > On Fri, Aug 22, 2008 at 09:23:43AM +0200, Pavel Machek wrote:
> > > > 
> > > > * Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > > > 
> > > > > > > The code in question is the ftraced() function in 
> > > > > > > kernel/trace/ftrace.c
> > > > > > 
> > > > > > Thanks, I'll have a look in a while.
> > > > > 
> > > > > Can you try the appended patch, please?
> > > > 
> > > > makes sense - i've applied it to tip/tracing/urgent, see the tidied up 
> > > > commit below.
> > > > 
> > > > It should be no big issue not being able to trace across suspend+resume 
> > > > - and that restriction will go away with Steve's build-time based mcount 
> > > > patching mechanism in v2.6.28.
> > > 
> > > Patch looks okay to me, but I'm not sure if another issue is not
> > > hiding under it. Did anyone actually test ftrace + suspend after
> > > applying this?
> > 
> > I just tested this patch - it didn't help ;(
> > 
> > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> > index 49f4c3f..02e41b2 100644
> > --- a/kernel/trace/ftrace.c
> > +++ b/kernel/trace/ftrace.c
> > @@ -27,6 +27,7 @@
> >  #include <linux/ctype.h>
> >  #include <linux/hash.h>
> >  #include <linux/list.h>
> > +#include <linux/freezer.h>
> >  
> >  #include <asm/ftrace.h>
> 
> This is needed to fix compilation, sorry for the omission.
> 
> Still, did you test ftrace + suspend with the original patch and your fix
> applied and if you did, then what happend?

Suspend works fine. When I hit power button I see some informations from
video card (nvidia), then screen goes black and monitor says "no signal"
and then I see the same informations from video card, then BIOS and GRUB.
When everything works fine, X comes back after first infos from video card.

Marcin