From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <440F0FA8.6080903@lanl.gov>
Date: Wed,  8 Mar 2006 10:08:56 -0700
From: Ronald G Minnich <rminnich@lanl.gov>
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To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
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Subject: [9fans] usb questions
Topicbox-Message-UUID: 0fba52e6-ead1-11e9-9d60-3106f5b1d025

I'm looking at usb and trying to understand something. I have two
systems that only have BARs for memory mapped IO for the USB controllers
(i.e. they are memory BARs, not I/O BARs). As I read the usbuhci code,
it appears that the controller only gets added if BAR[4] has a valid I/O
address; on these controllers it is always zero. I am about to kill a
tree and print the spec, but am wondering what's up here -- why does
plan 9 kernel only add a controller if it has an I/O address?

ron