[vdr] Re: No DMA used

[Sebastian Hesselbarth <sebastian.hesselbarth@gmx.de>]

MB> Greetings,

MB> for some reason my HD (Maxtor 80GB) doesn't uses DMA - but it is
MB> switched on (hdparm) and while booting it's seems to be enabled
MB> correctly. But the max. datarate is to low and it takes about 95% of
MB> cpu usage.

MB> I'm using Kernel 2.4.4-4GB (Suse 7.2) and it's an IBM Board with a
MB> P200. (The Bios reports only 8GB HD, but all space is available)

MB> ideas anyone?

MB> Ciao,
MB> Manne

maybe your chipset does not support UDMA!

try to force hdparm to use different DMA-modes:

1. 'hdparm /dev/hda' shows you the parameters currently set for hda
(check for use_dma=1)
2. 'hdparm -X64 /dev/hda' enables _U_DMA mode 1 (65=UDMA mode 2,etc)
   'hdparm -X32 /dev/hda' enables DMA mode 1 (33=DMA mode 2,etc)

maybe the parameters are wrong (esp. -Xnn calls) .. check 'man hdparm'
for the correct parameters!

your chipset will reject all modes it does not support when hdparm
tries to set it. so you will find the correct supported mode by try
all -X parameters.

bye Sebastian