Hi Kay, I got the below warning and the first "bad" commit is commit 8f46baaa7ec6cd0851794020b31958e64679dd26 Author: Felipe Balbi Date: Wed Feb 20 10:31:42 2013 +0200 base: core: WARN() about bogus permissions on device attributes Whenever a struct device_attribute is registered with mismatched permissions - read permission without a show routine or write permission without store routine - we will issue a big warning so we catch those early enough. Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman [ 11.581068] bus: 'rttest': add device rttest0 [ 11.581813] ------------[ cut here ]------------ [ 11.582568] WARNING: at /c/kernel-tests/src/linux/drivers/base/core.c:569 device_create_file+0x5a/0xa0() [ 11.584035] Write permission without 'store' [ 11.584793] Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc2-next-20130318 #21 [ 11.585902] Call Trace: [ 11.586318] [<8102d888>] warn_slowpath_common+0x68/0xa0 [ 11.587146] [<8151b77a>] ? device_create_file+0x5a/0xa0 [ 11.587982] [<8151b77a>] ? device_create_file+0x5a/0xa0 [ 11.588820] [<8102d91e>] warn_slowpath_fmt+0x2e/0x30 [ 11.589618] [<8151b77a>] device_create_file+0x5a/0xa0 [ 11.590523] [<81081faa>] init_rttest+0xaa/0x150 [ 11.591255] [<81082270>] ? handle_op+0x220/0x220 [ 11.591994] [<81081f00>] ? sysfs_test_status+0xf0/0xf0 [ 11.592838] [<821f7a92>] do_one_initcall+0x7f/0x128 [ 11.593642] [<821f7c1e>] kernel_init_freeable+0xe3/0x182 [ 11.594492] [<821f74d1>] ? do_early_param+0x7a/0x7a [ 11.595291] [<81c8ce2b>] kernel_init+0xb/0xd0 [ 11.596026] [<81cac5f7>] ret_from_kernel_thread+0x1b/0x28 [ 11.596990] [<81c8ce20>] ? rest_init+0x130/0x130 [ 11.597749] ---[ end trace 124d60cbc476f331 ]--- git bisect start 0e78c0989334e9c1d578ba25621de14e8441d8b4 08637024ab77f7defff1627cc8aedc2c6679ad8a -- git bisect good 5b4ab7cbdf1c0d93f5e7e14671c8b34ff081b928 # 10 2013-03-18 18:56:02 Merge remote-tracking branch 'slab/for-next' git bisect bad a9dd67e06c062671c880f62087a6fe6d4096ec39 # 0 2013-03-18 19:00:10 Revert "gpio/palmas: add in GPIO support for palmas charger" git bisect good e8196b632b87f568668394fdc8b5053aa7918885 # 10 2013-03-18 19:05:59 Merge remote-tracking branch 'regmap/for-next' git bisect good 157dfaac1f2922a3cbd90685339511cb97cad225 # 10 2013-03-18 19:12:52 staging: dwc2: fix compiler warnings git bisect good a14592896023adcab12307774c89284ce0744ce2 # 10 2013-03-18 19:17:44 staging: comedi: ni_labpc: fix common detach git bisect bad 9b53d29f3c8d2b9bfe73eb1dfb78a53b8c0fa2d7 # 0 2013-03-18 19:21:54 Merge remote-tracking branch 'usb/usb-next' git bisect bad 50418d050eaa3998e4be2936f5f05718909122ee # 0 2013-03-18 19:24:22 Merge remote-tracking branch 'tty/tty-next' git bisect good d9a9770f7baea6171aa66e4070bdb9bf6f0402f3 # 10 2013-03-18 19:30:13 Merge remote-tracking branch 'leds/for-next' git bisect good 20cc225bab6709408840e4400cd1a5c2b28c7a52 # 10 2013-03-18 19:37:15 tty: Fix spinlock flavor in non-atomic __tty_hangup() git bisect good afa80ccb4c7d39702dfb0832ce02a054848191a8 # 10 2013-03-18 19:43:40 sysrq: fix inconstistent help message of sysrq key git bisect bad 8f46baaa7ec6cd0851794020b31958e64679dd26 # 0 2013-03-18 19:48:42 base: core: WARN() about bogus permissions on device attributes git bisect good be871b7e54711479d3b9d3617d49898770830db2 # 10 2013-03-18 19:54:14 device: separate all subsys mutexes git bisect good be871b7e54711479d3b9d3617d49898770830db2 # 30 2013-03-18 20:01:22 device: separate all subsys mutexes git bisect bad 0e78c0989334e9c1d578ba25621de14e8441d8b4 # 0 2013-03-18 20:06:35 Add linux-next specific files for 20130318 git bisect good 3154d2d99b2718f54136409fc3836a90e896eedc # 30 2013-03-18 20:16:20 Revert "base: core: WARN() about bogus permissions on device attributes" git bisect bad 0e78c0989334e9c1d578ba25621de14e8441d8b4 # 0 2013-03-18 20:20:59 Add linux-next specific files for 20130318 Thanks, Fengguang