8.0-RC1: AMD CS5536 (Geode) USB 2.0 controller strange behavour

[Eugene Grosbein]

> %dd if=/dev/zero bs=64k of=/dev/da0 count=1000
> 
> It started to work, meantime iostat output was:
> 
>  63.62  17  1.05
>   0.00   0  0.00
>   0.00   0  0.00
>   0.00   0  0.00
>   0.00   0  0.00
>   0.00   0  0.00
>  64.00   2  0.15
>  62.31  83  5.06
>   0.25   0  0.00
>   0.00   0  0.00
>   0.00   0  0.00
> ^C
> 
> To this moment, dd has finished his work and printed:
> 
> 1000+0 records in
> 1000+0 records out
> 65536000 bytes transferred in 78.627073 secs (833504 bytes/sec)

After some googling, I've tried sysctl hw.usb.ehci.no_hs=1,
reconnected HDD and retried the test. iostat output was:

%iostat -d -K -w 10 da0
             da0
  KB/t tps  MB/s
  2.88   0  0.00
 63.19   8  0.49
 64.00  11  0.69
 64.00  11  0.69
 64.00  11  0.68
 64.00  11  0.69
 64.00  11  0.69
 64.00  11  0.69
 64.00  11  0.68
 64.00  11  0.69
 41.81   7  0.28
  0.00   0  0.00
^C

%dd if=/dev/zero bs=64k of=/dev/da0 count=1000
1000+0 records in
1000+0 records out
65536000 bytes transferred in 91.364733 secs (717301 bytes/sec)

So, this time no idle periods but I'm still not happy with the speed.

Eugene Grosbein