Messages in this thread | | | Date | Tue, 7 Aug 2012 08:58:53 +0100 | From | Russell King <> | Subject | Re: [PATCH 0/5] mfd: replace IORESOURCE_IO by IORESOURCE_MEM |
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On Tue, Aug 07, 2012 at 09:47:25AM +0800, Haojian Zhuang wrote: > On Tue, Aug 7, 2012 at 6:00 AM, Mark Brown > <broonie@opensource.wolfsonmicro.com> wrote: > > On Mon, Aug 06, 2012 at 10:31:24PM +0100, Russell King wrote: > > > >> Anyway, given that this thread is broken, there's no way for me to find > >> out what the _original_ issue is that you're talking about. So I'm going > >> to guess that it's come up because we're out of IORESOURCE bits. > > > > No, that's not it. What's happened is that Haojian has posted some > > patching changing all the _IO resources to _MEM in the Marvell PMIC > > drivers, I think because you yelled at him for using _IO when he > > reported that the changes in ioport_resource broke things a few releases > > ago. Obviously this doesn't achieve a huge amount, it's a misplaced > > cleanup. > > > It's because IO_SPACE_LIMIT is set as 0 if there's no PCI devices. But > IORESOURCE_IO is also used in PMIC mfd drivers to distinguish > different components. > > commit 04e1c83806e30ae339fc45def595960c7fef1697 > Author: Russell King <rmk+kernel@arm.linux.org.uk> > Date: Wed Jul 6 12:49:59 2011 +0100 > > ARM: io: add a default IO_SPACE_LIMIT definition > > Add a default IO_SPACE_LIMIT definition. Explain the chosen value and > suggest why platforms would want to make it larger. > > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> > > >> So, if we made this a numeric index, then we have 32 resource types > >> to deal with, and no need to bugger around with re-using an existing > >> type for something else. > > > > This seems sensible, and I'm sure if that change were made people would > > be delighed to use new resource types, but like I say nobody who's > > motivated to do anything here seems to have the time to do anything > > about it. > > > > Whoever looks at this would need to do some detective work, it does seem > > like there must have been a reason to use a bitmask here... > > Changing bitmask to a value for IORESOURCE type is a risk. I agree on Mark > that someone will complain on this.
We won't know that unless we try and propose to do it in patch form. From what I can see, there is nothing in the kernel which technically prevents us from doing this.
> Could we consider to expand the usage of IORESOURCE_IO? Maybe we can > use it for both ISA/PCI and IO related in chip.
If it's not clear, I am *completely* against this. It's a hack and bodge, and therefore doesn't belong in the kernel.
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of:
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