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

[Ric Moore]

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

-- 
My father, Victor Moore (Vic) used to say:
"There are two Great Sins in the world...
..the Sin of Ignorance, and the Sin of Stupidity.
Only the former may be overcome." R.I.P. Dad.
Linux user# 44256