[U-Boot] [PATCH v4 4/6] armv7: Use -march=armv7-a and thereby enable Thumb-2

[Aneesh V]

Hi Marek,

On 07/06/2012 04:32 PM, Tetsuyuki Kobayashi wrote:
> Hello,
>
> On 2012/07/07, at 8:02, Marek Vasut wrote:
>
>> Dear Aneesh V,
>>
>>> Enable -march=armv7-a for armv7 platforms if the tool-chain
>>> supports it. This in turn results in Thumb-2 code generated
>>> for these platforms if CONFIG_SYS_THUMB_BUILD is enabled.
>>>
>>> Signed-off-by: Aneesh V<aneesh at ti.com>
>>> ---
>>
>> For some reason, this patch breaks USB EHCI on mx51 efika boards. The board just
>> freezes instead of detecting USB devices. Reverting this patch fixes the issue.
>>
>> Note I use gcc 4.7.1 (!), might be compiler issue?
>>
>> Tom, can you try on one of your beagle-dogs please? :)
>>
>
> Just for your information,
> I doubt unaligned access causes this problem.
>
> My investigation is here,
> http://lists.denx.de/pipermail/u-boot/2012-June/127020.html
> My patch
> [PATCH] arm: armv7: add compile option	-mno-unaligned-access if available
> http://lists.denx.de/pipermail/u-boot/2012-July/127260.html

This makes sense. You might want to try this patch. Also, to be sure
that it's nothing to do with Thumb you can make sure you are not
enabling CONFIG_SYS_THUMB_BUILD.

best regards,
Aneesh