The branch main has been updated by imp:
URL:
https://cgit.FreeBSD.org/src/commit/?id=aa52c6bdd7b157b7c5d9612e4feac5c94f376df6
commit aa52c6bdd7b157b7c5d9612e4feac5c94f376df6
Author: Warner Losh <i...@freebsd.org>
AuthorDate: 2022-12-04 23:20:24 +0000
Commit: Warner Losh <i...@freebsd.org>
CommitDate: 2022-12-04 23:20:24 +0000
newbus: Create a knob to disable devices that fail to attach.
Normally, when a device fails to attach, we tear down the newbus state
for that device so that future driver loads can try again (maybe with a
different driver, or maybe with a re-loaded and fixed kld).
Sometimes, however, it is desirable to have the device fail
permanantly. We do this by calling device_disable() on a failed
attached, as well as keeping the device in DS_ATTACHING forever. This
prevents retries on that device. This is enabled via
hw.bus.disable_failed_devices=1 in either a hint via the loader, or at
runtime with a sysctl setting. Setting from 1 -> 0 at runtime will not
affect previously disabled devices, however: they remain disabled.
They can be re-enabled manually with devctl enable, however.
Sponsored by: Netflix
Reviewed by: gallatin, hselasky, jhb
Differential Revision: https://reviews.freebsd.org/D37517
---
sys/kern/subr_bus.c | 33 +++++++++++++++++++++++++++------
1 file changed, 27 insertions(+), 6 deletions(-)
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index 739484ad849a..b9615b033007 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -69,6 +69,10 @@ SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW | CTLFLAG_MPSAFE,
NULL,
SYSCTL_ROOT_NODE(OID_AUTO, dev, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
NULL);
+static bool disable_failed_devs = false;
+SYSCTL_BOOL(_hw_bus, OID_AUTO, disable_failed_devices, CTLFLAG_RWTUN,
&disable_failed_devs,
+ 0, "Do not retry attaching devices that return an error from DEVICE_ATTACH
the first time");
+
/*
* Used to attach drivers to devclasses.
*/
@@ -2533,12 +2537,29 @@ device_attach(device_t dev)
if ((error = DEVICE_ATTACH(dev)) != 0) {
printf("device_attach: %s%d attach returned %d\n",
dev->driver->name, dev->unit, error);
- if (!(dev->flags & DF_FIXEDCLASS))
- devclass_delete_device(dev->devclass, dev);
- (void)device_set_driver(dev, NULL);
- device_sysctl_fini(dev);
- KASSERT(dev->busy == 0, ("attach failed but busy"));
- dev->state = DS_NOTPRESENT;
+ if (disable_failed_devs) {
+ /*
+ * When the user has asked to disable failed devices, we
+ * directly disable the device, but leave it in the
+ * attaching state. It will not try to probe/attach the
+ * device further. This leaves the device numbering
+ * intact for other similar devices in the system. It
+ * can be removed from this state with devctl.
+ */
+ device_disable(dev);
+ } else {
+ /*
+ * Otherwise, when attach fails, tear down the state
+ * around that so we can retry when, for example, new
+ * drivers are loaded.
+ */
+ if (!(dev->flags & DF_FIXEDCLASS))
+ devclass_delete_device(dev->devclass, dev);
+ (void)device_set_driver(dev, NULL);
+ device_sysctl_fini(dev);
+ KASSERT(dev->busy == 0, ("attach failed but busy"));
+ dev->state = DS_NOTPRESENT;
+ }
return (error);
}
dev->flags |= DF_ATTACHED_ONCE;
