Re: 2.4.16-ben0 DVD block i/o breaks mouse, pmu
>> When doing block i/o on the dvd drive (dd if=/dev/hdc of=/dev/null),
>> the mouse moves randomly and the pmu reports spurious dead battery
>> conditions. During the dd, use of the trackpad causes random pointer
>> motion. The battery is intermittently reported at 2% or 3%, even when
>> fully charged and plugged in.
>I had a similar problem here. However, I was clued on IRC (credits go to
>Michael Daenzer) and a fix to the problem seems to be to just enable DMA
>and unmask IRQ via hdparm. This also works if one uses ide-scsi, just try
>hdparm -d1 -u1 /dev/hdx. (Replace x by c and do not read the manpage of
>hdparm, it is just too scary... :) ) So e.g. one can place the line
>post-install ide-scsi hdparm -u1 -d1 /dev/hdx in /etc/modutils/foobar and
The question is why DMA would have been disabled in the first place ?
The kernel is enabling DMA by default on all devices that support it
connected to the Apple IDE interface.