From: Pantelis Antoniou <panto@intracom•gr>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: linux-ppc-embedded <linuxppc-embedded@ozlabs•org>
Subject: Re: [RFC] handle access to non-present IO ports on 8xx
Date: Thu, 02 Jun 2005 10:04:40 +0300 [thread overview]
Message-ID: <429EAF88.8040507@intracom.gr> (raw)
In-Reply-To: <1117680392.31082.16.camel@gaston>
Benjamin Herrenschmidt wrote:
> On Wed, 2005-06-01 at 13:50 -0300, Marcelo Tosatti wrote:
>
> Hrm... removing a PCMCIA card triggers mchecks ? that is bad... With
> "proper" PCMCIA controllers, those are swallowed properly when the card
> is removed. The eating of the machine check is a bit too hackish to my
> taste... Better is to "not do that" by making sure the legacy crap isn't
> trying to tap unexisting ports, but then, if PCMCIA is also a
> problem...
>
8xx is not proper in any way whatsoever :)
There's no way to fix this thing with simple software hacks.
For example take a PCMCIA driver that's minding it's own businees,
when someone yanks the card out.
cli()
...
inb(xxx)
...
<----- card is yanked here
...
inb(yyy)
...
<----- MCE here
sti()
>
>>1) why does the current PowerMac version covers only inb() and not outb() ?
>>I had to add outb() exception table entries for 8xx.
>
>
> Not sure, maybe historical loss ? :) You should CC paulus
>
>
>>2) Is the same wanted for other embedded PPC's?
>
>
> It's up to you. It slows down those IOs, but on the other hand, inX/outX
> aren't supposed to be very common anymore, at least not with "fast"
> devices, and the IO itself is usually an order of magnitude slower than
> doing those syncs...
>
Fast ISA I/O. :)
>
>>3) How to make the misc.S exception entries and additional instructions
>>selectable only on the platform who need it? #ifdef does not sound
>>a good idea.
I wouldn't mind...
>>
>>Nevermind the "#ifdef CONFIG_ALL_PPC" crap - that needs to be done
>>properly.
>>
>>
Regards
Pantelis
P.S. Good job marcello :)
next prev parent reply other threads:[~2005-06-02 7:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-01 16:50 [RFC] handle access to non-present IO ports on 8xx Marcelo Tosatti
2005-06-02 2:46 ` Benjamin Herrenschmidt
2005-06-02 7:04 ` Pantelis Antoniou [this message]
2005-06-02 17:02 ` Marcelo Tosatti
2005-06-02 22:11 ` Benjamin Herrenschmidt
2005-06-03 12:08 ` Mark Chambers
2005-06-08 9:01 ` Marcelo Tosatti
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