[PATCH] workaround for mpc52xx erratum #364 (serial may not be reset in break state)

[Grant Likely]

On Mon, Nov 3, 2008 at 3:15 PM, Wolfram Sang <w.sang at pengutronix.de> wrote:
> On Mon, Nov 03, 2008 at 03:57:09PM -0600, Matt Sealey wrote:
>
>> > Optionally you can further
>>> reduce impact by checking if CONFIG_PPC_MPC5200_BUGFIX is defined.
>>
>> I would much prefer this.
>
> I submitted a patch to enable pipelining on a MPC5200B recently. It was
> disabled because of a bug in the MPC5200. The first version of this
> patch used MPC5200_BUGFIX and it was mentioned, that some people might
> want to run the same kernel on both kind of processors. So, the patch
> that went mainline checks for the PVR. Maybe we should stick to this
> here, too?

Of the two solutions:
1. Run-time selection must be done.
2. Compile-time removal of the bug fix path can also be done to lessen
runtime impact for kernels never run on older chips

My view is that #1 is non-negotiable.  #2 is a nice to have, but if it
doesn't incur any cost when disabled at runtime then I don't care.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.