Re: ehci-hcd affects hda speed

[Rene Herman <rene.herman@keyaccess.nl>]

On 20-03-08 06:08, Alessandro Suardi wrote:

> On Thu, Mar 20, 2008 at 1:31 AM, Rene Herman <rene.herman@keyaccess.nl> wrote:

>>  I do wonder -- is your hda throughput also the same before _ever_ attaching
>>  anything to the EHCI controller and after? In my case, the slow down only
>>  happened after switching on my external USB drive once, and would persist
>>  from that time until reboot (or unloading ehci-hcd, which I kept modular for
>>  exactly that reason).
>>
>>  The sleep time wasn't the core problem, so I wonder of later VIA chips do
>>  still have the active async schedule problem...
>>
>>  Alessandro? You said there still was a difference for you between no EHCI at
>>  all and EHCI after tweaking 4B as Lev showed. How much?
> 
> When used setpci to tweak the setting, my hdparm -t went
>  from 17 to 25MB/s on /dev/hda.
> 
> With your patch applied, now after booting it says 33MB/s for
>  hda and 37MB/s on hdb (and I can burn DVDs at a stable 6x
>  now, while growisofs backed off to 4x in less than a minute
>  before the patch).
> 
> If the patch does exactly what setpci did, then perhaps I had
>  other activity on hda at the moment I ran the test...

Yes, should be the exact same. It could be what I noted -- that you have the 
33/37 just after booting, and a drop to 25 again after having switched 
on/used a EHCI device for the first time? That would be interesting.

Rene.