HEADS UP: Check your devices' UDMA settings - *TEMPORARY* *WORKAROUND*

[Basil Chupin]

On 06/04/2011 15:53, Ric Moore wrote:
> On Wed, 2011-04-06 at 15:04 +1000, Basil Chupin wrote:
>> On 05/04/2011 15:51, Basil Chupin wrote:
>>> It appears that Bug #195221 has suddenly come back -- see
>>> https://bugs.launchpad.net/ubuntu/+bug/195221.
>>>
>>> This bug re-appeared on 1 April (my time, Australia, East Coast)
>>> because the previous day my logs showed that the UDMAs were being set
>>> correctly. The only thing which I can see is that on 1 April there was
>>> a kernel firmware upgrade but as I know nuffin' about kernels (or
>>> majors or even captains) this upgrade may have nothing to do with it.
>>>
>>> What the above Bug is about is that even though your HDD, for example,
>>> can do UDMA 133 the UDMA in fact gets set to UDMA 33 because some
>>> check concludes incorrectly that the device is connected with a
>>> 40-wire cable. Here is an example I just took from my dmesg log file:
>>>
>> [pruned]
>>
>> The temporary workaround for this problem is to add to the boot
>> parameters the following: libata.force=X:80c
>>
>> where X is the IDE line which is being affected by this UDMA problem. In
>> my case, the devices on line #2 are affected so I use libata.force=2:80c
>> and now the HDD and the DVDRW are being set to UDMA 100&  100, respectively.
>>
>> Using 'libata.force=X:80c' is working because libata is actually
>> statically embedded in the kernel; if it was not then you would use
>> 'force=X:80c'.
>>
>> (Now I have to go and read up on grub 2 to see how I can insert this
>> workaround in grub without having to add this everything to the boot
>> parameters at boot time.)
> Glad to see you beat that bugger-bear! Man, it has been an uphill climb
> for you to get this far. I tip my wayward4now hat at ya! :) Ric

I do it for humanity's sake, I tell you! Tirelessly and without any 
consideration of myself! For no reward, except perhaps for a gratuitous 
small, simple, single, spoken quietly (more like whispered...) - "Thank 
you."

(I'm starting to believe this shit so I better stop :-) !)

Now all I need is for someone to tell me how to get this fix into grub 
so that it is executed whenever I boot up. I read the grub2 doco and I 
am buggered if I can get grub2 to automatically boot with this fix in 
its boot parameters :-( . Had no hassles with openSUSE 11.4 which is 
using the old grub: just type in the fix on a line in the menu.lst and 
reboot. But grub2? Oh no, thank you very mucho! The doco for grub2 in 
Ubuntu docs speak of The Startup Manager which 'will do all sorts of 
things' for you if you want to change the parameters in grub2. BS! You 
have a choice of changing ~4 parameters in grub2. Sheesh! As usual, 
something simple is turned into something only geeks can understand :-( .

BC

--
"I believe what I am programmed to believe."
A robot in Futuruma