"Unknown symbol __udivdi3" with rev >= 11873

"Unknown symbol __udivdi3" with rev >= 11873

[David Ward]

Revision 11873 (committed earlier today) has broken the cx18 driver for 
me, with the line "cx18: Unknown symbol __udivdi3" appearing in dmesg 
when the module tries to load.  I'm using Ubuntu 8.04.2 which uses 
kernel 2.6.24 and gcc 4.2.4.

I also wanted to express my appreciation to Mauro for fixing the build 
for older kernels today, as it is very desirable for me to use a 
distribution/kernel which has long-term support and updates, but I 
simply need to add a DVB driver that wasn't part of the older kernel.

Thanks so much.

David Ward

Re: "Unknown symbol __udivdi3" with rev >= 11873

[Michael Krufky]

On Thu, May 28, 2009 at 12:05 AM, David Ward <david.ward@gatech.edu> wrote:
> Revision 11873 (committed earlier today) has broken the cx18 driver for me,
> with the line "cx18: Unknown symbol __udivdi3" appearing in dmesg when the
> module tries to load.  I'm using Ubuntu 8.04.2 which uses kernel 2.6.24 and
> gcc 4.2.4.
>
> I also wanted to express my appreciation to Mauro for fixing the build for
> older kernels today, as it is very desirable for me to use a
> distribution/kernel which has long-term support and updates, but I simply
> need to add a DVB driver that wasn't part of the older kernel.
>
> Thanks so much.
>
> David Ward

Let it be known that this issue only affects 32bit kernels.  I believe
the offending line of code is here:

fsc = ((((u64)sc) * 28636360)/src_decimation) >> 13L;

(cc added to Andy Walls)

-Mike Krufky

Re: "Unknown symbol __udivdi3" with rev >= 11873

[David Ward]

On 05/28/2009 03:12 PM, Michael Krufky wrote:
> On Thu, May 28, 2009 at 12:05 AM, David Ward<david.ward@gatech.edu>  wrote:
>    
>> Revision 11873 (committed earlier today) has broken the cx18 driver for me,
>> with the line "cx18: Unknown symbol __udivdi3" appearing in dmesg when the
>> module tries to load.  I'm using Ubuntu 8.04.2 which uses kernel 2.6.24 and
>> gcc 4.2.4.
>>
>> I also wanted to express my appreciation to Mauro for fixing the build for
>> older kernels today, as it is very desirable for me to use a
>> distribution/kernel which has long-term support and updates, but I simply
>> need to add a DVB driver that wasn't part of the older kernel.
>>
>> Thanks so much.
>>
>> David Ward
>>      
> Let it be known that this issue only affects 32bit kernels.  I believe
> the offending line of code is here:
>
> fsc = ((((u64)sc) * 28636360)/src_decimation)>>  13L;
>
> (cc added to Andy Walls)
>
> -Mike Krufky
>    
Some Google searching seems to suggest that the correct thing to do here 
is to use the 'do_div' macro for the division, which is declared in 
<asm/div64.h>:

http://www.captain.at/howto-udivdi3-umoddi3.php

David

Re: "Unknown symbol __udivdi3" with rev >= 11873

[Michael Krufky]

On Thu, May 28, 2009 at 5:43 PM, David Ward <david.ward@gatech.edu> wrote:
> On 05/28/2009 03:12 PM, Michael Krufky wrote:
>>
>> On Thu, May 28, 2009 at 12:05 AM, David Ward<david.ward@gatech.edu>
>>  wrote:
>>
>>>
>>> Revision 11873 (committed earlier today) has broken the cx18 driver for
>>> me,
>>> with the line "cx18: Unknown symbol __udivdi3" appearing in dmesg when
>>> the
>>> module tries to load.  I'm using Ubuntu 8.04.2 which uses kernel 2.6.24
>>> and
>>> gcc 4.2.4.
>>>
>>> I also wanted to express my appreciation to Mauro for fixing the build
>>> for
>>> older kernels today, as it is very desirable for me to use a
>>> distribution/kernel which has long-term support and updates, but I simply
>>> need to add a DVB driver that wasn't part of the older kernel.
>>>
>>> Thanks so much.
>>>
>>> David Ward
>>>
>>
>> Let it be known that this issue only affects 32bit kernels.  I believe
>> the offending line of code is here:
>>
>> fsc = ((((u64)sc) * 28636360)/src_decimation)>>  13L;
>>
>> (cc added to Andy Walls)
>>
>> -Mike Krufky
>>
>
> Some Google searching seems to suggest that the correct thing to do here is
> to use the 'do_div' macro for the division, which is declared in
> <asm/div64.h>:
>
> http://www.captain.at/howto-udivdi3-umoddi3.php
>
> David


Patches welcome :-)

-MiKE