Date: Wed, 11 Jul 2007 08:44:02 +0200 (CEST) From: Raaf <raaf@zen.mooo.com> To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/114492: device_attach() doesn't unset devclass on error Message-ID: <20070711064402.EDE292D@zen.mooo.com> Resent-Message-ID: <200707110650.l6B6o2EC015171@freefall.freebsd.org>
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>Number: 114492
>Category: kern
>Synopsis: device_attach() doesn't unset devclass on error
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Jul 11 06:50:01 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator: Raaf
>Release: FreeBSD 6.2-STABLE i386
>Organization:
>Environment:
System: FreeBSD zen.mooo.com 6.2-STABLE FreeBSD 6.2-STABLE #10: Wed Jul 11 08:00:54 CEST 2007 raaf@zen.mooo.com:/usr/obj/usr/src/sys/RANI i386
>Description:
device_attach() doesn't unset devclass on error.
I have a Sony Ericsson mobile phone that has 9 USB interfaces.
Interface 1: Is handled by umodem(4)
Interface 2: Is the associated data interface for interfaces 1 and 3
Interface 3: Is also handled by umodem(4)
Interface 8: Is handled by umass(4)
device_attach() fails on interface 3 because interface 3 requires data
interface 2 which is already taken by interface 1.
Thats is not a big problem.
However because device_attach() doesn't unset devclass on error, all
subsequent calls on the remaining device interfaces will be called
with devclass set to that of the umodem driver, and umass match/attach
will never be called for interface 8.
Note that this current code in device_attach() doesn't do anything:
----------------------------------------------------------------------
/* Unset the class; set in device_probe_child */
if (dev->devclass == 0)
device_set_devclass(dev, 0);
----------------------------------------------------------------------
>How-To-Repeat:
>Fix:
The following patch fixes it for me.
--- patch-subr_bus.c begins here ---
--- sys/kern/subr_bus.c.orig Wed Jul 11 07:50:24 2007
+++ sys/kern/subr_bus.c Wed Jul 11 07:56:54 2007
@@ -2322,6 +2322,7 @@
device_probe_and_attach(device_t dev)
{
int error;
+ int hasclass = (dev->devclass != 0);
GIANT_REQUIRED;
@@ -2344,6 +2345,9 @@
return (error);
}
error = device_attach(dev);
+ /* Unset the class; set in device_probe_child */
+ if(error && !hasclass)
+ device_set_devclass(dev, NULL);
return (error);
}
@@ -2378,9 +2382,6 @@
if ((error = DEVICE_ATTACH(dev)) != 0) {
printf("device_attach: %s%d attach returned %d\n",
dev->driver->name, dev->unit, error);
- /* Unset the class; set in device_probe_child */
- if (dev->devclass == 0)
- device_set_devclass(dev, 0);
device_set_driver(dev, NULL);
device_sysctl_fini(dev);
dev->state = DS_NOTPRESENT;
--- patch-subr_bus.c ends here ---
>Release-Note:
>Audit-Trail:
>Unformatted:
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