linux-kernel - Re: [PATCH] Fix floppy hibernation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Tue, 2 Jun 2009 23:25:02 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Ondrej Zary <linux@...nbow-software.org>
Cc:	linux-kernel@...r.kernel.org, mingo@...e.hu, rjw@...k.pl
Subject: Re: [PATCH] Fix floppy hibernation

On Wed, 3 Jun 2009 08:13:26 +0200 Ondrej Zary <linux@...nbow-software.org> wrote:

> > > +static int floppy_resume(struct platform_device *dev)
> > > +{
> > > +	int fdc;
> > > +
> > > +	for (fdc = 0; fdc < N_FDC; fdc++)
> > > +		if (FDCS->address != -1)
> > > +			user_reset_fdc(-1, FD_RESET_ALWAYS, 0);
> > > +
> > > +	return 0;
> > > +}
> >
> > The patch changes the driver so that it calls user_reset_fdc() for each
> > device at resume-time.
> >
> > Why?  What effect does this have on the hardware and why does it fix
> > things?
> 
> I don't know at all, it's complete guesswork. The first thing I tested was 
> rmmod floppy && modprobe floppy after resume - it worked. Narrowing the 
> initialization code down resulted in this patch.

lol, OK.  I added this to the changelog:

  This fix resets the floppy controller on resume.  It was
  experimentally determined to bring the controller back to life - we
  don't really know why it works.

  floppy_init() does the same thing at boot/modprobe time.

Let's see how it goes...  If someone reports breakage then we can
always change the driver so that activation of your new code requires a
module parameter.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/