Subject: port-alpha/21472: USB device interferes with IDE device; interrupt lossage
To: None <>
From: None <>
List: netbsd-bugs
Date: 05/06/2003 01:46:37
>Number:         21472
>Category:       port-alpha
>Synopsis:       USB device interferes with IDE device; interrupt lossage
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    port-alpha-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon May 05 23:47:00 UTC 2003
>Originator:     Reinoud Zandijk
>Release:        NetBSD 1.5 till at least 1.6R
NetBSD 1.6-current kernel of 20030505 on an DEC Alpha 500au. Big IDE disc, 
no SCSI discs. No USB devices.

When the `ohci* at pci? dev? function?' is enabled in the kernel 
configuration IDE interrupts seem to be intercepted/delivered at the USB 
device that doesnt understand them and rejects them. This gives rise to IDE 
timeouts, USB sheduling overruns (with NO DEVICES!!!) etc.

I've dug into this before and in conversations it seemed that the ohci
driver isnt fully Alpha aware in that the bus-barriers are not allways done
right. The last time i tried it still had this problem so nowadays i've 
disabled ohci by default.
Boot a kernel with ohci enabled.
Disable ohci and disable usb at ohci