Messages in this thread Patch in this message |  | | Date | Sat, 4 Jan 2003 14:11:52 -0600 (CST) | From | Matt Domsch <> | Subject | Re: kobject_init() sets kobj->subsys wrong? |
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> Your recent patch creating find_bus("scsi") always returns NULL. I see > that's because bus_subsys.list is empty.
In kobject_add(), with kobj->subsys = NULL, this kobject (embedded inside struct subsystem embedded inside struct bus_type) never gets added to either it's parent's list, nor to the (NULL) subsystem's list. It appears that the object can be on either a parent's list or a subsystem's list, but not both, by virtue of there being only one struct list_head entry in struct kobject.
You're far more versed in how this should work than I. Some ideas...
1) in bus_register(), don't set bus->subsys.parent = &bus_subsys, instead set bus->subsys.kobj.subsys = &bus_subsys. I did this, and now find_bus() works as expected, but now the busses created don't have parents unless they're specified prior to calling bus_register(), so this doesn't seem quite right.
===== linux-2.5-edd-work/drivers/base/bus.c 1.26 vs edited ===== --- 1.26/drivers/base/bus.c Sun Dec 1 23:22:04 2002 +++ edited/linux-2.5-edd-work/drivers/base/bus.c Sat Jan 4 13:58:31 2003 @@ -495,7 +520,7 @@ down(&bus_sem); strncpy(bus->subsys.kobj.name,bus->name,KOBJ_NAME_LEN); - bus->subsys.parent = &bus_subsys; + bus->subsys.kobj.subsys = &bus_subsys; subsystem_register(&bus->subsys); snprintf(bus->devsubsys.kobj.name,KOBJ_NAME_LEN,"devices");
2) set both bus->subsys.parent and bus->subsys.kobj.subsys, but then fix the test in kobject_add() to put the object on the subsystem's list if possible, then fall back to the parent list otherwise. Again, doesn't seem quite right.
3) Add another struct list_head to kobject to let it reside on both a parent list and a subsystem list if either exist.
There are probably other options. Please advise.
Thanks, Matt
-- Matt Domsch Sr. Software Engineer, Lead Engineer, Architect Dell Linux Solutions www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com
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