Re: [PATCH 4/7] hvc_console: Fix race between hvc_close andhvc_remove

From: Stephen Rothwell
Date: Fri Mar 26 2010 - 06:54:34 EST


Hi Amit,

On Fri, 26 Mar 2010 15:28:21 +0530 Amit Shah <amit.shah@xxxxxxxxxx> wrote:
>
> On (Fri) Mar 26 2010 [14:43:56], Sachin Sant wrote:
> >
> > I too ran into this issue as reported by Anton. Unfortunately in my
> > case the following suggested patch does not help boot the powerpc
> > box successfully. The boot still hangs with following messages

I have been getting this on my linux-next boot tests for a while as well.

> Was the hang you saw before applying this patch at the same place / for
> the same reason?

I get the same hangs with and without the patch. Paulus bisected it
(again) to the commit below and reverting that commit fixes the problem.

> OK, this gets even murkier. I don't know why taking a few krefs modifies
> hvc_console behaviour to such an extent.
>
> > Just to confirm i too am facing same issue as reported by Anton,
> > reverted commit e74d098c66543d0731de62eb747ccd5b636a6f4c and that allowed
> > by box to boot successfully.
>
> Which module uses hvc_console in your case?

I assume hcv_vio.

I also tested using "init=/bin/bash" as a kernel command line option and
the console worked while I was running bash, but everything was very
sluggish. Then when I did "exec /sbin/init" the console hung completely
- sysrq (^O) didn't even work any more (it did while I was running bash).

--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx
http://www.canb.auug.org.au/~sfr/

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