Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [RFC PATCH 4/4] ARM: Xilinx: Adding Xilinx board support | Date | Tue, 3 May 2011 12:35:41 +0200 |
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On Tuesday 03 May 2011, Russell King - ARM Linux wrote: > On Tue, May 03, 2011 at 09:58:14AM +0200, Arnd Bergmann wrote: > > On Tuesday 03 May 2011 01:01:18 Russell King - ARM Linux wrote: > > > It is preferable to use the same mapping, as it ensures that you're not > > > going to create incompatible aliases. > > > > Is aliasing a problem for MMIO mappings? I would think that you can > > ioremap registers anywhere and as often as you want because they are > > never cacheable. > > Provided the type and sharability is identical then there is no problem. > I wasn't referring to multiple ioremap()s of the same region - that > should be fine as the same attributes will be used. If you mix ioremap() > and iotable_init() then you _could_ have problems if you don't use > MT_DEVICE in the iotable. > > What I'm basically saying is that mixing the methods of creating these > mappings makes it much easier to get tripped up over these issues.
Ok, makes sense.
Thanks,
Arnd
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