Re: prevent swsusp with PAE

["Randy.Dunlap" <rdunlap@xenotime.net>]

On Fri, 1 Sep 2006 00:35:21 +0200 Pavel Machek wrote:

> Hi!
> 
> > Pavel Machek <pavel@suse.cz> wrote:
> > 
> > > If HIGHMEM64G and swsusp are used at the same time, nasty random
> > > crashes happen during resume. Cause is known; prevent that
> > > combination.
> > > 
> > > I guess I'd like to see this one in 2.6.18...
> > > 
> > > Signed-off-by: Pavel Machek <pavel@suse.cz>
> > > 
> > > ---
> > > commit acb3b411ec93f827b25b8481d53670c5c9195d89
> > > tree f52cd5518e34af16fe5ae28064717bcc95929f28
> > > parent cd03e183c58e6e7073e054a7fe335cf50c61fe2f
> > > author <pavel@amd.ucw.cz> Thu, 31 Aug 2006 15:52:34 +0200
> > > committer <pavel@amd.ucw.cz> Thu, 31 Aug 2006 15:52:34 +0200
> > > 
> > >  include/asm-i386/suspend.h |    8 ++++++++
> > >  1 files changed, 8 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/include/asm-i386/suspend.h b/include/asm-i386/suspend.h
> > > index 08be1e5..01cd812 100644
> > > --- a/include/asm-i386/suspend.h
> > > +++ b/include/asm-i386/suspend.h
> > > @@ -16,6 +16,15 @@ arch_prepare_suspend(void)
> > >  		printk(KERN_ERR "PSE is required for swsusp.\n");
> > >  		return -EPERM;
> > >  	}
> > > +
> > > +#ifdef CONFIG_X86_PAE
> > > +	printk(KERN_ERR "swsusp is incompatible with PAE.\n");
> > > +	/* This is actually instance of the same problem. We need
> > > +	   identity mapping self-contained in swsusp_pg_dir, and PAE
> > > +	   prevents that. Solution could be copied from x86_64. */
> > > +	return -EPERM;
> > > +#endif
> > > +
> > >  	return 0;
> > >  }
> > 
> > Why not do this in Kconfig??
> 
> Well, Kconfig does not provide natural place for comments, and
> disappearing config option is sure to confuse people. But of course I
> can do it.

Documentation/kbuild/kconfig-language.txt includes a "comment" keyword.

USB-storage uses it to suggest that SCSI + SCSI disk support need
to be enabled for usb-storage.

---
~Randy