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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Tabi Timur-B04825 <B04825@freescale.com>
Cc: "borntraeger@de.ibm.com" <borntraeger@de.ibm.com>,
	Hendrik Brueckner <brueckner@linux.vnet.ibm.com>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	Anton Blanchard <anton@samba.org>
Subject: Re: hvc_console change results in corrupt oops output
Date: Tue, 05 Jul 2011 16:22:43 +1000	[thread overview]
Message-ID: <1309846963.14501.270.camel@pasglop> (raw)
In-Reply-To: <CAOZdJXW0Lota0ZuEnOHhsU93v7WmvYztEMyfg+UsMKxFdoXNXQ@mail.gmail.com>

On Tue, 2011-07-05 at 04:17 +0000, Tabi Timur-B04825 wrote:
> On Mon, Jul 4, 2011 at 9:24 AM, Hendrik Brueckner
> <brueckner@linux.vnet.ibm.com> wrote:
> 
> > I will check this again for my hvc_iucv back-end.  Meanwhile a found
> > an old thread discussing the same issue.  It covers some differences
> > between console and ttys which actually does not matter for hvc-backend
> > because of the shared put_chars() routine.
> >
> > You can read the thread on lkml.org: http://lkml.org/lkml/2009/10/15/149
> 
> I started that thread.  After much soul searching, we came to the
> conclusion that HVC is not compatible with hypervisors that return
> BUSY on writes. 

That is a fun conclusion considering that hvc has been written for the
pseries hypervisor which ... can return BUSY on writes :-)

> So I threw out my HVC driver and rewrote it as a
> standard console and TTY driver.  That driver is waiting to be
> included in the 3.1 kernel.

Sucktastic.

We just need to fix HVC properly.

Cheers,
Ben.

  reply	other threads:[~2011-07-05  6:23 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-04 10:57 hvc_console change results in corrupt oops output Anton Blanchard
2011-07-04 13:56 ` Benjamin Herrenschmidt
2011-07-04 14:24   ` Hendrik Brueckner
2011-07-05  4:17     ` Tabi Timur-B04825
2011-07-05  6:22       ` Benjamin Herrenschmidt [this message]
2011-07-05 13:51         ` Tabi Timur-B04825
2011-07-05 14:28         ` [RFC] [PATCH] hvc_console: improve tty/console put_chars handling Hendrik Brueckner
2011-07-06  7:49           ` Anton Blanchard
2011-07-06  7:50           ` [PATCH 1/2]: " Anton Blanchard
2011-07-06  7:51           ` [PATCH 2/2]: powerpc/pseries/hvconsole: Fix dropped console output Anton Blanchard

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