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Re: DMA not permitted since 2.6.14



Le dimanche 11 décembre 2005 à 23:52 +0100, Hendrik Sattler a écrit :
> David LIMA wrote:
> > 
> > I'm running Debian SID with linux-image-2.6-686, since few days i'm
> > facing DMA problems after upgrading kernel to 2.6.14 (from stock).
> > Hdparm  reports "operation not permitted" when I try do activate DMA.
> > 
> > I have read http://lists.debian.org/debian-user/2005/11/msg00410.html
> > and recompile my kernel but still same issue.
> [...]
> > /dev/hda:
> >  UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 udma6
> >
> > /dev/hdc:
> >  UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 udma6
> >  * signifies the current active mode
> > 
> > Has someone any clue about this problem that slow down my system ?
> 
> Actually, no clue what you are complaining about: both drives run with UDMA5, 
> there not much more what you can enable with respect to DMA transfers.

Hi, Henrik 

For sure, DMA is not running, my system is very slow each time I access
my disks (CPU eating).
_______________________
hdparm -tT /dev/hd{a,c}

/dev/hda:
 Timing cached reads:   768 MB in  2.01 seconds = 382.53 MB/sec
 Timing buffered disk reads:    8 MB in  3.26 seconds =   2.45 MB/sec

/dev/hdc:
 Timing cached reads:   144 MB in  2.00 seconds =  71.87 MB/sec
 Timing buffered disk reads:    8 MB in  3.42 seconds =   2.34 MB/sec
______________________
hdparm -v /dev/hd{a,c}

/dev/hda:
 multcount    =  1 (on)
 IO_support   =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  0 (off)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 65535/16/63, sectors = 160086528, start = 0

/dev/hdc:
 multcount    =  1 (on)
 IO_support   =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  0 (off)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 19929/255/63, sectors = 320173056, start = 0

________________________
hdparm -d1 /dev/hd{a,c}

/dev/hda:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

/dev/hdc:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

TIA, 

David

> 
> HS
> 



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