Alan Cox wrote:
2. The cs5535 ide driver doesn't seem to be able to recognize the
newer CS5536 controller for IDE.
Switch to libata as most distributions have already done and enable the
pata_cs5536 driver, which is designed for this hardware.
Thanks for the suggestion - It made a *big* difference.
Here's a couple of timings (sequential reads from the CF) that show the difference in
performance. I didn't do writes because I'm never sure what various CF's do inside and
don't have confidence that seemingly similar CF writes have consistent times.
Using the generic IDE driver:
[root@board-1 /root]# time dd if=/dev/hda2 of=/dev/null bs=512
3572352+0 records in
3572352+0 records out
real 16m 18.64s
user 0m 0.76s
sys 1m 28.08s
Using the PATA CS5536 driver:
[root@board-1 /root]# time dd if=/dev/sda2 of=/dev/null bs=512
3572352+0 records in
3572352+0 records out
real 1m 11.41s
user 0m 0.47s
sys 0m 3.56s
In other words, on sequential reads, I'm seeing a roughly 13x fold improvement in clock
time and an 11x improvement in sys+user cpu.
[It also seemed to fix another weird thing that started with 2.6.28, the disappearance of
the stdout from linuxrc and rc.sysinit - the kernel messages still hit the console but the
stuff from those two startup scripts went into never never land (even though, as apparent
from their side effects, they still executed properly.)]
I guess I now need to go through my system and make sure that any hard coded "hda" are
changed to "sda".
As for the other issues mentioned during this very helpful discussion, of which I
comprehended about 50%:
Do folks still want me to try that patch? (Now that the problem I've been having seems
fixed, and being lazy by nature, I'll do it if it is helpful but otherwise I'd prefer to
skip it.)
As for the question of why I have the SD driver - The ALIX2 boards (which, by the way are
Geode LX, not the older Geode) has USB and I want to sometimes plug external USB drives
into 'em. I thought that the SD driver is needed for that, am I in error?
By-the-way, I'm happy (modulo my previously mentioned lazy nature) to run tests on ALIX2
and ALIX3 boards should anyone need it.
Thanks,
--karl--
Karl Auerbach
Santa Cruz, CA
http://www.cavebear.com/
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