W dniu 30.04.2012 23:12, Alan Stern pisze:
It isn't a software issue. You've got a hardware problem; either the IPKVM itself, or the connecting cable, or your computer's EHCI controller is bad. The only reason the device worked without the retry logic is because it failed so completely that the kernel was forced to run it at full speed (12 Mb/s) instead of high speed (480 Mb/s). With the retry logic present, the device was barely workable at high speed (but it probably didn't work well enough to be very useful).
Oh. Thanks for the info. Is there a way to force the device into 12Mb/s mode? I don't care about performance as the bottleneck is my Internet link on the client, anyway. The retry logic rendered the console unusable (not just slow, completely no keyboard or redirected media).
Have you tried plugging the IPKVM into a different computer to see if it behaves any better?
Nope. The IPKVM is a proprietary addon card without any cables (plugs into a dedicated slot on the motherboard). Another identical machine is misbehaving the exact same way (retry messages in dmesg), so either I'm just unlucky, or it's a wider issue. Still, a few others are working fine (no retry messages; though I did not check the KVM recently). All the machines are in a rather remote DC, so I'm unlikely to muck with the hardware any time soon.
Are there any diagnostics possible to determine what is broken (i.e. the KVM card or the controller)? IIRC plugging a physical USB-based KVM worked fine, although that might have been an older kernel, without the retry logic.
Best regards, Grzegorz Nosek -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
