Re: tlbia and PPC603

[Etsushi Kato <ekato@ees.hokudai.ac.jp>]

Hi Ben,
Thank you for your reply.

On Wed, Jun 19, 2002 at 05:51:37AM +0200,
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

> Try without the ethernet card and switch IDE DMA off and tell me if it is
> stable, there could be some cache coherency issues with some of the chipsets
> used on these machines.

I was able to use both IDE DMA and ethernet card on
linux-2.4.13-pre3-ben0 without problems.
Anyway I tried rsync kernel without CONFIG_BLK_DEV_IDEDMA_PMAC_AUTO
and compiled tulip as modules (and not loaded), but it still dropped
to xmon randomly.

> Another thing you can try is in set_context(), add an isync on the line
> that contain the label "3:" as the doc states a context synchronizing
> instruction should also be used for data sync. before mtsrin.

I changed set_context() and  it might improve stableness somewhat, but
still dropped to xmon at some occasion.

> Hrm... just in case, try also changing the definition of tlbia macro
> in ppc_asm.h to put isync's inside the loop, both before and after the
> tlbie's (add too much is no problem for such a test) and tell me if it
> has any effect.

With this change combined with set_context() change, crashes
disappeared during boot time (tested 10 times and all trial
succeeded).  It is really improvement.  But still sometimes (5 times
per 10) dropped to xmon while sshd is working by ssh connection from
other machine.


Thanks,
--
Etsushi Kato
ekato@ees.hokudai.ac.jp

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