[PATCH] ARM: PJ4: allow building in Thumb-2 mode

[Ard Biesheuvel]

On 24 November 2014 at 18:36, Gregory CLEMENT
<gregory.clement at free-electrons.com> wrote:
> Hi Arnd,
>
> On 24/11/2014 18:17, Arnd Bergmann wrote:
>> On Monday 24 November 2014 16:34:47 Ard Biesheuvel wrote:
>>> On 24 November 2014 at 16:29, Arnd Bergmann <arnd at arndb.de> wrote:
>>>> On Monday 24 November 2014 12:56:40 Ard Biesheuvel wrote:
>>>>> Two files that get included when building the multi_v7_defconfig target
>>>>> fail to build when selecting THUMB2_KERNEL for this configuration.
>>>>>
>>>>> In both cases, we can just build the file as ARM code, as none of its
>>>>> symbols are exported to modules, so there are no interworking concerns.
>>>>> In the iwmmxt.S case, add ENDPROC() declarations so the symbols are
>>>>> annotated as functions, resulting in the linker to emit the appropriate
>>>>> mode switches.
>>>>>
>>>>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>>>>
>>>> Ah, very nice. I tried this before, but my version didn't actually
>>>> work, presumably because I didn't know about the ENDPROC() stuff.
>>>>
>>>> Have you tested this on a machine that has IWMMXT enabled?
>>>>
>>>
>>> No, I don't have access to such a machine, unfortunately.
>>
>> Adding a few mvebu folks to Cc, maybe one of them can test your patch.
>
> Actually even it is a feature of the PJ4 machine non of the mvebu machines
> currently use it. I only see this configuration enabled for the pxa family.
> So I think you would have more feedback with the pxa maintainers/owners.
>

Are you saying PJ4 should be dropped from 'default' here?

config IWMMXT
        bool "Enable iWMMXt support"
        depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
        default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B

-- 
Ard.