[PATCH 5/9] ARM: dts: Add GPMC node for OMAP2, OMAP4 and OMAP5

Benoit Cousson b-cousson at ti.com
Thu Mar 14 11:45:02 EDT 2013


On 03/11/2013 06:56 PM, Jon Hunter wrote:
> 
> On 03/09/2013 06:42 AM, Ezequiel Garcia wrote:
>> On Fri, Mar 8, 2013 at 10:25 PM, Javier Martinez Canillas
>> <javier at dowhile0.org> wrote:
>>> On Fri, Mar 8, 2013 at 10:41 PM, Jon Hunter <jon-hunter at ti.com> wrote:
>>>>
>>>> Yes you are correct. In general, I have been trying to stay some-what
>>>> consistent with what hwmod was doing as this was being auto-generated by
>>>> some hardware design specs and I believe they wanted to eventually get
>>>> to the point where DT files would be auto-generated too for OMAP.
>>>> Furthermore my understanding is that the smallest page that can be
>>>> mapped by the kernel for ARM is 4kB. So if you declare it as 0x2d0 or
>>>> 0x1000 it will map a 4kB page (I could be wrong here).
>>>>
>>>> I don't have any strong feelings here but will do what the consensus
>>>> prefers.
>>>>
>>>
>>> Yes, you are right here.
>>>
>>> I forget that ioremap() does a page-aligned mapping and since the
>>> minimum page size for ARM is 4KB as you said, there is no difference
>>> between using 0x2d0 and 0x1000. Sorry for the noise.
>>>
>>
>> Certainly, I don't have strong feelings about this.
>> FWIW, mvebu maintainers imposes a "minimal" address space request
>> policy.
>>
>> On the other side, it seems to me we shouldn't look at internal kernel
>> implementation (i.e. ioremap page-alignment) to make this decision.
> 
> I agree with that. I am not sure if Tony/Benoit have any comments on
> what they would like to do here to be consistent for the omap bindings.

Yes, I full agree with that as well. The size should be purely HW
related. So we should not take any assumption about the page size /
alignment.

Regards,
Benoit




More information about the linux-arm-kernel mailing list