[alsa-devel] [PATCH] ASoC: prevent compilers from optimising pll calculation into __aeabi__uldivmod

[Barry Song]

2011/4/27 Barry Song <21cnbao at gmail.com>:
> 2011/4/27 Mark Brown <broonie at opensource.wolfsonmicro.com>:
>> On Wed, Apr 27, 2011 at 11:00:18PM +0800, Barry Song wrote:
>>> 2011/4/27 Mark Brown <broonie at opensource.wolfsonmicro.com>
>>
>>> > If we do have to do something in the callers rather than in do_div() the
>>> > annotation seems substantially more taseful than inserting a random asm
>>> > into the code.
>>
>>> I agree. for this patch which will not be applied, people can just get
>>> information about how to workaround the gcc issue while they have the
>>> same problem. google can find there are other people who failed to
>>> compile wm8974 module too. eg.
>>> http://irclogs.ubuntu.com/2010/03/30/%23ubuntu-arm.txt
>>
>>> Andrew Stubbs, Michael Hope in Linaro's toolchain team are working
>>> hard on this gcc issue. there have been many update today:
>>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48783
>>
>> Is this just some Linaro toolchain that has the issue rather than a
>> vanilla GCC release?  If so and they fix the compiler bug it doesn't
>> seem terribly useful to bodge it in mainline.
>>
>
> i am guessing it is a generic gcc issue since Michael posted it at
> http://gcc.gnu.org/bugzilla not Linaro's Launchpad. not sure :-)

Linaro doesn't exist yet when the discussion happened at
http://irclogs.ubuntu.com/2010/03/30/%23ubuntu-arm.txt discussion:

" [19:03] <nosse1> I got this while compiling: "ERROR:
"__aeabi_uldivmod" [sound/soc/codecs/snd-soc-wm8974.ko] undefined!"
[19:04] <nosse1> Now, I can disable the driver alltogether, but is
this related to the CSL cross compiler?
[19:04] <hrw> nosse1: google should give answer - common problem it was
[19:04] <nosse1> hehe - sorry, you're right
"