Re: [LAU] UA-101

From: Colin Fletcher <colin.m.fletcher@email-addr-hidden>
Date: Fri Feb 26 2010 - 19:15:33 EET

Clemens Ladisch wrote:

> Please try toggling the kernel config option CONFIG_USB_EHCI_TT_NEWSCHED
> ("Improved Transaction Translator scheduling (EXPERIMENTAL)") of the
> EHCI driver.

Here are some more logs.

ua-1000-ehci-oldsched.log is the result with CONFIG_USB_EHCI_TT_NEWSCHED
not set: the URBs still complete out-of-order.

Out of curiousity, because I have a dual-core CPU, I also tried booting
the CONFIG_USB_EHCI_TT_NEWSCHED=y kernel with maxcpus=0
(ua-1000-ehci-newsched-maxcpus-0.log) and maxcpus=1
(ua-1000-ehci-newsched-maxcpus-1.log), to see what would happen.

Curiously, maxcpus=0 shows the URBs completing in order, except that
submitting URB 20 is delayed until after 0-19 have completed. maxcpus=1
has the URBs out-of-order. I don't know what to conclude from this;
maybe it makes some sense to you?

Is there anything else you'd like me to try? Or anything else you might
need to know about my system?

Is there a more appropriate list for this, or are we still on-topic for LAU?

Cheers,
Colin.

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Received on Fri Feb 26 20:15:05 2010

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