Messages in this thread | | | Date | Fri, 02 Mar 2001 09:31:00 -0600 | From | Thomas Dodd <> | Subject | Re: DMA on a AMD7409 controller with kernel 2.4.2 |
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> On Thu, 1 Mar 2001, Hylke van der Schaaf wrote: > > > With kernet 2.2.18 DMA mode for my harddisks worked just fine, > > getting IDE DMA working on an AMD7409 controller with kernel 2.4.2 is a problem. > > > > questions: > > Why is DMA disabled on revision < C4? > > How can I gat DMA working again? > > in 2.2.18 I get: > > hylke:/home/hylke# hdparm -tT /dev/hda > > > > /dev/hda: > > Timing buffer-cache reads: 128 MB in 0.89 seconds =143.82 MB/sec > > Timing buffered disk reads: 64 MB in 2.85 seconds = 22.46 MB/sec > > ---------------------------- > > > > All was fine. > > I compiled 2.4.2, with: > > CONFIG_AMD7409_OVERRIDE=y
I'm not using this, since my drives are not UDMA66 or UDMA100
> > hylke:/home/hylke# hdparm -v /dev/hda > > > > /dev/hda: > > multcount = 16 (on) > > I/O support = 1 (32-bit) > > unmaskirq = 1 (on) > > using_dma = 0 (off) > > keepsettings = 0 (off) > > nowerr = 0 (off) > > readonly = 0 (off) > > readahead = 8 (on) > > geometry = 2495/255/63, sectors = 40088160, start = 0 > > hylke:/home/hylke# hdparm -tT /dev/hda > > > > /dev/hda: > > Timing buffer-cache reads: 128 MB in 0.90 seconds =142.22 MB/sec > > Timing buffered disk reads: 64 MB in 12.59 seconds = 5.08 MB/sec
I get 148.8 and 12 MB/sec on my IBM-DTTA-351010 drives. I get the same message about no single word DMA due to chip revision. # hdparm -v /dev/hda
/dev/hda: multcount = 16 (on) I/O support = 3 (32-bit w/sync) unmaskirq = 0 (off) using_dma = 1 (on) keepsettings = 0 (off) nowerr = 0 (off) readonly = 0 (off) readahead = 8 (on) geometry = 19650/16/63, sectors = 19807200, start = 0
What does /proc/ide/hda/settings show? What about /proc/ide/amd74xx ?
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