[PATCH v2 2/3] ARM: omap4: Correct definition of do_wfi() forCONFIG_THUMB2_KERNEL

[Dave Martin]

Hi,

On Tue, Dec 7, 2010 at 6:28 AM, Santosh Shilimkar
<santosh.shilimkar at ti.com> wrote:
> Dave,
>> -----Original Message-----
>> From: linaro-dev-bounces at lists.linaro.org [mailto:linaro-dev-
>> bounces at lists.linaro.org] On Behalf Of Dave Martin
>> Sent: Monday, December 06, 2010 11:06 PM
>> To: linux-arm-kernel at lists.infradead.org
>> Cc: Tony Lindgren; Dave Martin; linux-omap at vger.kernel.org; linaro-
>> dev at lists.linaro.org
>> Subject: [PATCH v2 2/3] ARM: omap4: Correct definition of do_wfi()
>> forCONFIG_THUMB2_KERNEL
>>
>> For the Thumb-2 case, the "wfi" mnemonic is used, since in this
>> case the tools will necessarily be new enough to support it.
>>
>> Signed-off-by: Dave Martin <dave.martin at linaro.org>
>> ---
>> KernelVersion: 2.6.37-rc4
>
> The choice of opcode instead of instruction here was not because
> of toolchain. The problem was it breaks multi-omap build where
> ARMv6 and ARMv7 are build together.
>
> For this reason I NAK this patch.

You can't built a kernel for pre-v7 platforms with
CONFIG_THUMB2_KERNEL: the code can't run on those platforms because
they don't support Thumb-2.

So anything inside #ifdef CONFIG_THUMB2_KERNEL can assume v7/Thumb-2
capable (and hence reasonably new) tools.

I'll follow up shortly with a patch to the generic ARM Kconfig to make
this explicit, so that ARCH_OMAP2 and THUMB2_KERNEL can't accidentally
be configured together.

Cheers
---Dave