13 messages in org.freebsd.freebsd-archnewbus flaw| From | Sent On | Attachments |
|---|---|---|
| Dag-Erling Smørgrav | May 11, 2004 7:39 am | |
| Doug Rabson | May 11, 2004 8:08 am | |
| Poul-Henning Kamp | May 11, 2004 8:12 am | |
| John-Mark Gurney | May 11, 2004 6:02 pm | |
| Dag-Erling Smørgrav | May 12, 2004 6:27 am | |
| John-Mark Gurney | May 12, 2004 10:41 am | |
| Dag-Erling Smørgrav | May 12, 2004 10:48 am | |
| John-Mark Gurney | May 12, 2004 10:53 am | |
| Dag-Erling Smørgrav | May 12, 2004 1:30 pm | |
| Doug Rabson | May 13, 2004 1:27 am | |
| Dag-Erling Smørgrav | May 13, 2004 3:46 am | |
| Doug Rabson | May 13, 2004 5:34 am | |
| M. Warner Losh | May 13, 2004 9:06 am |
| Subject: | newbus flaw | |
|---|---|---|
| From: | John-Mark Gurney (gurn...@efn.org) | |
| Date: | May 12, 2004 10:53:44 am | |
| List: | org.freebsd.freebsd-arch | |
Dag-Erling Sm?rgrav wrote this message on Wed, May 12, 2004 at 15:26 +0200:
John-Mark Gurney <gurn...@efn.org> writes:
You are incorrect in assuming you can't find out if another child already exists.. Usually this is a problem of properly allocating resources so that you know the other child exists. Since you are using identify, you already don't have a "self describing" bus, which means that you have to either use hints, or another method to make sure that your device doesn't already exist.
It's not quite that simple. See the block comment at the top of src/sys/dev/ichwd/ichwd.c for an explanation.
Sorry, I had an out of date cvsup and hadn't received ichwd yet.
You're always going to be a child of nexus, and since I assume from the comment that there can only ever be one child. Also, why do you find_child w/ unit number 0, but then add a child with unit -1? Why not add it unit 0, and make it fail if that already exists?
Also, it seems to me that if dev already exists, that you shouldn't reset the driver and desc. This should be harmless, but if for some reason you are called on an attached device, it could cause problems.
-- John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."