Messages in this thread | | | From | Gabriele Paoloni <> | Subject | RE: [PATCH V5 2/3] ARM64 LPC: Add missing range exception for special ISA | Date | Wed, 9 Nov 2016 14:51:01 +0000 |
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> -----Original Message----- > From: One Thousand Gnomes [mailto:gnomes@lxorguk.ukuu.org.uk] > Sent: 09 November 2016 13:55 > To: Arnd Bergmann > Cc: Mark Rutland; Yuanzhichang; catalin.marinas@arm.com; > will.deacon@arm.com; robh+dt@kernel.org; bhelgaas@google.com; > olof@lixom.net; linux-arm-kernel@lists.infradead.org; > lorenzo.pieralisi@arm.com; linux-kernel@vger.kernel.org; Linuxarm; > devicetree@vger.kernel.org; linux-pci@vger.kernel.org; linux- > serial@vger.kernel.org; minyard@acm.org; benh@kernel.crashing.org; > liviu.dudau@arm.com; zourongrong@gmail.com; John Garry; Gabriele > Paoloni; zhichang.yuan02@gmail.com; kantyzc@163.com; xuwei (O); > marc.zyngier@arm.com > Subject: Re: [PATCH V5 2/3] ARM64 LPC: Add missing range exception for > special ISA > > > I think it is a relatively safe assumption that there is only one > > ISA bridge. A lot of old drivers hardcode PIO or memory addresses > > It's not a safe assumption for x86 at least. There are a few systems > with > multiple ISA busses particularly older laptops with a docking station.
Mmmm right...now the point is that this kind of special devices appearing as a special ISA bus will probably never appear on x86 platforms (I guess).
So maybe it is a safe assumption because of this...?
Thanks
Gab
> > > when talking to an ISA device, so having multiple instances is > > already problematic. > > PCMCIA devices handle it themselves so are ok. I'm not clear how the > dual > PIIX4 configuration used in the older IBM laptop docks actually worked > so > I assume the transaction went out of both bridges and providing one of > them responded the other kept silent as you simply stuffed the card > into > the dock and it worked. > > Alan
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