From: Knut Petersen <Knut_Petersen@t-online.de>
To: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Subject: dvb_device_open: possible circular locking dependency detected
Date: Mon, 26 Aug 2013 08:45:58 +0200 [thread overview]
Message-ID: <521AF9A6.4080907@t-online.de> (raw)
As long as I use the "Hauppauge WinTV Nova-HD-S2", nobody seems to be
really interested in silencing deadlock warnings triggered by dvb_device_open().
dvb lockdep problems are old, but they still exist.
See: http://permalink.gmane.org/gmane.linux.drivers.video-input-infrastructure/27027
[ 186.583006] ======================================================
[ 186.583009] [ INFO: possible circular locking dependency detected ]
[ 186.583013] 3.11.0-rc6-main+ #29 Not tainted
[ 186.583016] -------------------------------------------------------
[ 186.583019] kaffeine/1986 is trying to acquire lock:
[ 186.583022] (&fe->lock){+.+.+.}, at: [<f8c4a0d9>] videobuf_dvb_find_frontend+0x1b/0x43 [videobuf_dvb]
[ 186.583036]
[ 186.583036] but task is already holding lock:
[ 186.583039] (minor_rwsem){++++..}, at: [<f8c340a1>] dvb_device_open+0x26/0xfa [dvb_core]
[ 186.583054]
[ 186.583054] which lock already depends on the new lock.
[ 186.583054]
[ 186.583058]
[ 186.583058] the existing dependency chain (in reverse order) is:
[ 186.583062]
[ 186.583062] -> #2 (minor_rwsem){++++..}:
[ 186.583068] [<c01682d4>] lock_acquire+0x9b/0xd5
[ 186.583077] [<c0532cea>] down_write+0x20/0x3c
[ 186.583084] [<f8c343f8>] dvb_register_device+0x158/0x20a [dvb_core]
[ 186.583093] [<f8c3a28a>] dvb_register_frontend+0x15b/0x18d [dvb_core]
[ 186.583104] [<f8c4a297>] videobuf_dvb_register_bus+0xd1/0x2c7 [videobuf_dvb]
[ 186.583110] [<f8c51eb1>] cx8802_dvb_probe+0x201b/0x2136 [cx88_dvb]
[ 186.583118] [<f851787b>] cx8802_register_driver+0x121/0x1f7 [cx8802]
[ 186.583129] [<f8c5f01c>] 0xf8c5f01c
[ 186.583135] [<c01003b5>] do_one_initcall+0x6f/0xea
[ 186.583140] [<c0170443>] load_module+0x168a/0x1985
[ 186.583146] [<c01707b7>] SyS_init_module+0x79/0x91
[ 186.583151] [<c0535045>] syscall_call+0x7/0xb
[ 186.583156]
[ 186.583156] -> #1 (dvbdev_register_lock){+.+.+.}:
[ 186.583162] [<c01682d4>] lock_acquire+0x9b/0xd5
[ 186.583167] [<c05326a1>] mutex_lock_nested+0x3a/0x298
[ 186.583172] [<f8c342c2>] dvb_register_device+0x22/0x20a [dvb_core]
[ 186.583181] [<f8c34968>] dvb_dmxdev_init+0xbb/0xf7 [dvb_core]
[ 186.583189] [<f8c4a33f>] videobuf_dvb_register_bus+0x179/0x2c7 [videobuf_dvb]
[ 186.583195] [<f8c51eb1>] cx8802_dvb_probe+0x201b/0x2136 [cx88_dvb]
[ 186.583202] [<f851787b>] cx8802_register_driver+0x121/0x1f7 [cx8802]
[ 186.583208] [<f8c5f01c>] 0xf8c5f01c
[ 186.583212] [<c01003b5>] do_one_initcall+0x6f/0xea
[ 186.583217] [<c0170443>] load_module+0x168a/0x1985
[ 186.583221] [<c01707b7>] SyS_init_module+0x79/0x91
[ 186.583226] [<c0535045>] syscall_call+0x7/0xb
[ 186.583231]
[ 186.583231] -> #0 (&fe->lock){+.+.+.}:
[ 186.583237] [<c01677cd>] __lock_acquire+0xebd/0x154c
[ 186.583242] [<c01682d4>] lock_acquire+0x9b/0xd5
[ 186.583246] [<c05326a1>] mutex_lock_nested+0x3a/0x298
[ 186.583251] [<f8c4a0d9>] videobuf_dvb_find_frontend+0x1b/0x43 [videobuf_dvb]
[ 186.583257] [<f8c4fcef>] cx88_dvb_bus_ctrl+0x25/0x9d [cx88_dvb]
[ 186.583263] [<f8c39e63>] dvb_frontend_open+0x12f/0x2ca [dvb_core]
[ 186.583273] [<f8c34103>] dvb_device_open+0x88/0xfa [dvb_core]
[ 186.583281] [<c01db1ab>] chrdev_open+0xfc/0x11c
[ 186.583287] [<c01d6332>] do_dentry_open+0x169/0x203
[ 186.583293] [<c01d656f>] finish_open+0x2c/0x37
[ 186.583297] [<c01e2b45>] do_last+0x818/0xa03
[ 186.583303] [<c01e2f35>] path_openat+0x205/0x4d2
[ 186.583308] [<c01e343d>] do_filp_open+0x2a/0x63
[ 186.583312] [<c01d749e>] do_sys_open+0x140/0x1bb
[ 186.583317] [<c01d7536>] SyS_open+0x1d/0x1f
[ 186.583322] [<c0535045>] syscall_call+0x7/0xb
[ 186.583327]
[ 186.583327] other info that might help us debug this:
[ 186.583327]
[ 186.583331] Chain exists of:
[ 186.583331] &fe->lock --> dvbdev_register_lock --> minor_rwsem
[ 186.583331]
[ 186.583340] Possible unsafe locking scenario:
[ 186.583340]
[ 186.583343] CPU0 CPU1
[ 186.583346] ---- ----
[ 186.583348] lock(minor_rwsem);
[ 186.583352] lock(dvbdev_register_lock);
[ 186.583357] lock(minor_rwsem);
[ 186.583361] lock(&fe->lock);
[ 186.583365]
[ 186.583365] *** DEADLOCK ***
[ 186.583365]
[ 186.583369] 2 locks held by kaffeine/1986:
[ 186.583372] #0: (dvbdev_mutex){+.+...}, at: [<f8c34097>] dvb_device_open+0x1c/0xfa [dvb_core]
[ 186.583385] #1: (minor_rwsem){++++..}, at: [<f8c340a1>] dvb_device_open+0x26/0xfa [dvb_core]
[ 186.583398]
[ 186.583398] stack backtrace:
[ 186.583403] CPU: 0 PID: 1986 Comm: kaffeine Not tainted 3.11.0-rc6-main+ #29
[ 186.583406] Hardware name: /i915GMm-HFS, BIOS 6.00 PG 09/14/2005
[ 186.583410] 00000000 c0a3600c f0d79c5c c052f17a f0d79c8c c052d253 c06b1687 c06b1553
[ 186.583421] c06b151b c06b153c c06b151b f0d79cd4 f0ed64e0 00000002 f0ed695c f0ed6974
[ 186.583432] f0d79d04 c01677cd f0ed695c 00000002 00000002 00000000 ffffe000 f0d79ffc
[ 186.583443] Call Trace:
[ 186.583450] [<c052f17a>] dump_stack+0x16/0x18
[ 186.583456] [<c052d253>] print_circular_bug+0x233/0x240
[ 186.583462] [<c01677cd>] __lock_acquire+0xebd/0x154c
[ 186.583469] [<c01682d4>] lock_acquire+0x9b/0xd5
[ 186.583476] [<f8c4a0d9>] ? videobuf_dvb_find_frontend+0x1b/0x43 [videobuf_dvb]
[ 186.583483] [<f8c4a0d9>] ? videobuf_dvb_find_frontend+0x1b/0x43 [videobuf_dvb]
[ 186.583489] [<c05326a1>] mutex_lock_nested+0x3a/0x298
[ 186.583496] [<f8c4a0d9>] ? videobuf_dvb_find_frontend+0x1b/0x43 [videobuf_dvb]
[ 186.583503] [<f8c4a0d9>] videobuf_dvb_find_frontend+0x1b/0x43 [videobuf_dvb]
[ 186.583511] [<f8c4fcef>] cx88_dvb_bus_ctrl+0x25/0x9d [cx88_dvb]
[ 186.583522] [<f8c39e63>] dvb_frontend_open+0x12f/0x2ca [dvb_core]
[ 186.583532] [<f8c340e0>] ? dvb_device_open+0x65/0xfa [dvb_core]
[ 186.583542] [<f8c34103>] dvb_device_open+0x88/0xfa [dvb_core]
[ 186.583548] [<c01db1ab>] chrdev_open+0xfc/0x11c
[ 186.583554] [<c01d6332>] do_dentry_open+0x169/0x203
[ 186.583559] [<c01db0af>] ? cdev_put+0x1f/0x1f
[ 186.583564] [<c01d656f>] finish_open+0x2c/0x37
[ 186.583569] [<c01e2b45>] do_last+0x818/0xa03
[ 186.583575] [<c01e00ff>] ? inode_permission+0x44/0x47
[ 186.583580] [<c01e015c>] ? link_path_walk+0x5a/0x690
[ 186.583586] [<c01e2f35>] path_openat+0x205/0x4d2
[ 186.583592] [<c0168a78>] ? trace_hardirqs_on+0xb/0xd
[ 186.583598] [<c01e343d>] do_filp_open+0x2a/0x63
[ 186.583606] [<c01ecd6f>] ? __alloc_fd+0xbf/0xc9
[ 186.583612] [<c01d749e>] do_sys_open+0x140/0x1bb
[ 186.583617] [<c01d8e9d>] ? __fput+0x1af/0x1c8
[ 186.583623] [<c0530000>] ? decode_winbond+0x60/0x159
[ 186.583629] [<c01d7536>] SyS_open+0x1d/0x1f
[ 186.583634] [<c0535045>] syscall_call+0x7/0xb
[ 186.583640] [<c0530000>] ? decode_winbond+0x60/0x159
[ 187.238501] cx24116_firmware_ondemand: Waiting for firmware upload (dvb-fe-cx24116.fw)...
[ 187.241340] cx24116_firmware_ondemand: Waiting for firmware upload(2)...
[ 192.841700] cx24116_load_firmware: FW version 1.26.90.0
[ 192.841717] cx24116_firmware_ondemand: Firmware upload complete
cu,
Knut
next reply other threads:[~2013-08-26 6:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-26 6:45 Knut Petersen [this message]
[not found] <521AF818.3070208@t-online.de>
2013-08-26 10:15 ` dvb_device_open: possible circular locking dependency detected Andy Walls
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