[gentoo-user] Measuring USB "packet loss"

[gentoo-user] Measuring USB "packet loss"

[Chris Stankevitz]

Hello,

Some background: I'm running an experiment that is sensitive to USB
latency of a few milliseconds.  During a typical overnight run I
encounter a handful such "latency events" and I am trying to
understand why they happen.  If you can recommend kernel
settings/hacks that will decrease USB latency, please share!

===

Q: How can I retrieve a count of USB transmissions that failed or were
retransmitted? (analogous to ifconfig on ethernet)

Regarding this question:

a) Can you answer it?

b) Can you recommend something I can read that will answer it?

c) Can you recommend somewhere for me to ask this question where it
can be answered?

===

Thank you!

Chris

Re: [gentoo-user] Measuring USB "packet loss"

[James Cloos]

>>>>> "CS" == Chris Stankevitz <chrisstankevitz@gmail.com> writes:

CS> c) Can you recommend somewhere for me to ask this question where it
CS> can be answered?

I'd try one of:

linux-usb@vger.kernel.org
libusb-devel@lists.sourceforge.net
libusbx-devel@lists.sourceforge.net

They are on gmane.org as:

gmane.linux.usb.general
gmane.comp.lib.libusb.devel.general
gmane.comp.lib.libusbx.devel

-JimC
-- 
James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6

[gentoo-user] Re: Measuring USB "packet loss"

[Chris Stankevitz]

On Tue, Nov 6, 2012 at 12:07 PM, Chris Stankevitz
<chrisstankevitz@gmail.com> wrote:
> Q: How can I retrieve a count of USB transmissions that failed or were
> retransmitted? (analogous to ifconfig on ethernet)

Short answer from linux-usb: This is not possible.  For lower latency,
try the -rt kernel.

Chris