Hi David, On Sun, 4 May 2008 21:24:45 -0700, David Brownell wrote: > This changes how the I2C core iterates devices connected to a given > i2c_adapter, making it use driver model facilities instead of the > deprecated i2c_adapter.clients list. The two functions affected are > i2c_del_adapter() and i2c_del_driver(). > > This is something of a bugfix: updates to that list are protected by a > lock (i2c_adapter.clist_lock) which is completly ignored by those two > iteration loops ... > > Signed-off-by: David Brownell <[EMAIL PROTECTED]> > --- > Builds fine, and I have a hard time seeing this break. But this > hasn't really been tested. > > drivers/i2c/i2c-core.c | 91 > +++++++++++++++++++++++++------------------------ > 1 file changed, 48 insertions(+), 43 deletions(-)
I remember doing the same change several months ago, but finally dropping the patch because it was deadlocking. Your patch has the exact same problem: rmmod'ing a legacy i2c driver deadlocks. rmmod D ffffffff80443380 0 4669 4652 ffff81002e177cc8 0000000000000086 ffff81002e1dc190 ffff81003f8a1240 ffff81002e177cc8 ffff81002e177cc8 ffff81002e226b90 7fffffffffffffff 0000000000000002 7fffffffffffffff ffff81003f172648 ffff81002e177d48 Call Trace: [<ffffffff8042c175>] schedule_timeout+0x95/0xd0 [<ffffffff802c3ce0>] ? sysfs_remove_dir+0x60/0x80 [<ffffffff8042bf31>] wait_for_common+0xd1/0x160 [<ffffffff80225080>] ? default_wake_function+0x0/0x10 [<ffffffff8030d4e7>] ? kobject_put+0x27/0x60 [<ffffffff8042c058>] wait_for_completion+0x18/0x20 [<ffffffff803b4fe2>] i2c_detach_client+0x82/0xc0 [<ffffffffa02e4071>] :lm90:lm90_detach_client+0x71/0x90 [<ffffffff803b4f0b>] i2c_do_detach_client+0x8b/0xe0 [<ffffffff803b4e80>] ? i2c_do_detach_client+0x0/0xe0 [<ffffffff8038d473>] device_for_each_child+0x33/0x60 [<ffffffff803b45e6>] i2c_del_driver+0x106/0x120 [<ffffffffa02e4f10>] :lm90:sensors_lm90_exit+0x10/0x12 [<ffffffff8024d41e>] sys_delete_module+0x12e/0x1f0 [<ffffffff8020b43b>] system_call_after_swapgs+0x7b/0x80 I even seem to remember that you had been able to explain this deadlock back then... Obviously I can't take your patch until this is solved. Thanks, -- Jean Delvare _______________________________________________ i2c mailing list [email protected] http://lists.lm-sensors.org/mailman/listinfo/i2c
