Re: Yet another HDIO_SET_DMA failed problem
(I don't see a way to put on a References: line in pine. I'm sorry
for screwing the threading.)
On Mon, 11 Aug 2003, Alvin Oga <aoga@ns.Linux-Consulting.com> wrote:
> On Mon, 11 Aug 2003 tmcd@panix.com wrote:
> > hdparm -d 1 -k 1 /dev/hda
> > HDIO_SET_DMA failed: operation not permitted
>
> do you know what the "-k 1" setting does ???
-k Get/set the keep_settings_over_reset flag for the drive. When
this flag is set, the driver will preserve the -dmu options
over a soft reset, (as done during the error recovery
sequence).
> do you know if the disk drive supports that option ??
It does not appear to be a drive option; it seems to be a driver
option. I tried "-d 1" without "-k 1" as well.
> > if my scrawled notes are to be trusted. One person had
> > recommended that the second line indicated that the alim15x3
> > module needed to be loaded. I did, and bandwidth dropped from 4
> > MB/s to 1 MB/s!
>
> looks like the alim15x3 module is the right choice ..
Would you please explain that? I just wrote that I tried it and
bandwidth DECREASED by a factor of 4. That hardly seems like the
correct driver.
> you might also need to check other disk options
> - what other options is set or not set
> - what other disks is connected on the same ide cable
As I mentioned in my original e-mail:
(Other parameters (-c, -u, -A, -a, -m) have no noticable effect on
the speed reported by "hdparm -t", whether under my normal kernel
or under Knoppix.)
The only other drive on that cable is a CD drive, which sat idle
during the tests. I didn't touch the cable while switching between
Knoppix and my Debian kernel, so I don't see how that could be a
factor.
--
Tim McDaniel, tmcd@panix.com; tmcd@us.ibm.com is my work address
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