Re: [Qemu-devel] [PATCHv2 4/8] Store IDE bus id in IDEBus structure for easy access.

[Gleb Natapov]

On Fri, Nov 05, 2010 at 05:31:38PM +0100, Markus Armbruster wrote:
> Gleb Natapov <address@hidden> writes:
> 
> > On Fri, Nov 05, 2010 at 03:04:05PM +0100, Markus Armbruster wrote:
> [...]
> >> >> >> There has been quite some discussion on "canonical path" on the list,
> >> >> >> but no consensus.  Ironically, one of the places where we got stuck 
> >> >> >> was
> >> >> >> ISA.  You cut right through that, so that's progress.  Maybe people
> >> >> >> aren't looking ;)
> >> >> > That is funny since the problem was already solved looong time ago. 
> >> >> > Just
> >> >> > look at Open Firmware device path. They are capable of addressing all
> >> >> > devices just fine, ISA devices included. What specific problem you had
> >> >> > with ISA bus? 
> >> >> 
> >> >> Lack of consensus.  I was in favour of using I/O base, just like you do.
> >> >> There were worries about ISA devices not using any I/O ports.
> >> > There is a solution for that problem for almost 15 years and we are
> >> > still looking for consensus on qemu list?! Here is ISA device binding
> >> > spec for Open Firmware: 
> >> > http://playground.sun.com/1275/bindings/isa/isa0_4d.ps 
> >> > If ISA device have no IO ports MMIO is used.
> >> 
> >> Precedence should promote consensus, but it can't replace it.  If you
> >> can push the list to consensus, more power to you.
> > I do not see disagreement right now :) You are saying you agree. Blue
> > Swirl asked me to use Open Firmware so I assume he agrees to. So who is
> > against and what are his arguments?
> 
> Start here:
> 
> http://lists.nongnu.org/archive/html/qemu-devel/2010-06/msg01618.html

I saw this in fact. The wouldn't agree with this device path proposal
too. It mixes qemu internal names (which is a big no-no for my purpose)
and bus addresses. Paul made sensible points there and if you look
closely what he proposes is what I implemented here. Regarding ISA
("busses that don't have a consistent addressing scheme" he called it)
he himself proposed to use address of the first IO port/memory region
as an ID. This is what is already implemented by my patch.

--
                        Gleb.