Problems with disabling Optimization

Problems with disabling Optimization

[Prabhu nath]

Dear All,

               Disabling O2 and Os on Kernel building, I am getting the
following error. Can you please help me in debugging this.
       Saw some info on the net, but could not resolve it.

ERROR: "intel_gmbus_is_forced_bit" [drivers/gpu/drm/i915/i915.ko] undefined!
ERROR: "__udivdi3" [drivers/gpu/drm/i915/i915.ko] undefined!
make[2]: *** [__modpost] Error 1
make[1]: *** [modules] Error 2
make: *** [sub-make] Error 2

Regards,
Prabhu
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Problems with disabling Optimization

[Dave Hylands]

Hi Prabhu,

On Thu, Jun 2, 2011 at 3:28 AM, Prabhu nath <gprabhunath@gmail.com> wrote:
> Dear All,
>
> ?????????????? Disabling O2 and Os on Kernel building, I am getting the
> following error. Can you please help me in debugging this.
> ?????? Saw some info on the net, but could not resolve it.
>
> ERROR: "intel_gmbus_is_forced_bit" [drivers/gpu/drm/i915/i915.ko] undefined!
> ERROR: "__udivdi3" [drivers/gpu/drm/i915/i915.ko] undefined!

This means that your code is trying to do some type of 64-bit
arithmetic (probably a divide) which isn't directly supported in the
kernel.

There is a do_div macro/function from arch/arm/include/asm/div64.h, or
arch/x86/include/asm/div64.h

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com

Problems with disabling Optimization

[Ali Bahar]

>                Disabling O2 and Os on Kernel building, I am getting the
> following error. Can you please help me in debugging this.

> ERROR: "intel_gmbus_is_forced_bit" [drivers/gpu/drm/i915/i915.ko] undefined!
> ERROR: "__udivdi3" [drivers/gpu/drm/i915/i915.ko] undefined!
> make[2]: *** [__modpost] Error 1
> make[1]: *** [modules] Error 2
> make: *** [sub-make] Error 2

It's been a while since I (last) disabled these, but I did not run
into a compilation error because of it. And I recall the box needing
i915, too.  Is this a case of simply needing to do a _clean_ build?

later,
ali
PS IIRC, a CONFIG option exists _but_ I also had to edit a makefile to
get everything disabled -- though don't ask me when and where that
was!  :-)

Problems with disabling Optimization

[Dave Hylands]

Hi Ali,

On Sun, Jun 5, 2011 at 7:52 PM, Ali Bahar <ali@internetdog.org> wrote:
>> ? ? ? ? ? ? ? ?Disabling O2 and Os on Kernel building, I am getting the
>> following error. Can you please help me in debugging this.
>
>> ERROR: "intel_gmbus_is_forced_bit" [drivers/gpu/drm/i915/i915.ko] undefined!
>> ERROR: "__udivdi3" [drivers/gpu/drm/i915/i915.ko] undefined!
>> make[2]: *** [__modpost] Error 1
>> make[1]: *** [modules] Error 2
>> make: *** [sub-make] Error 2
>
> It's been a while since I (last) disabled these, but I did not run
> into a compilation error because of it. And I recall the box needing
> i915, too. ?Is this a case of simply needing to do a _clean_ build?

It's a case of needing to replace the 64-bit division with something
that involves a call to do_div, or otherwise eliminating the 64 bit
division.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com