Hi,
I have regular udev freeze with Cinterion 3G modem.
After enabling modem i got following:
[ 1081.188415] INFO: task udevd:1165 blocked for more than 120 seconds.
[ 1081.195159] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1081.203491] udevd D c0519bac 0 1165 1101 0x00000001
[ 1081.203643] Backtrace:
[ 1081.203887] [<c05196b0>] (__schedule+0x0/0x5f0) from [<c0519e48>] (schedule+0x8c/0x90)
[ 1081.204040] [<c0519dbc>] (schedule+0x0/0x90) from [<c051a0b0>] (schedule_preempt_disabled+0x30/0x40)
[ 1081.204193] [<c051a080>] (schedule_preempt_disabled+0x0/0x40) from [<c0518b94>] (__mutex_lock_slowpath+0x160/0x1cc)
[ 1081.204315] r4:e80fe89c r3:00000000
[ 1081.204620] [<c0518a34>] (__mutex_lock_slowpath+0x0/0x1cc) from [<c0518c64>] (mutex_lock+0x64/0x7c)
[ 1081.204711] r7:c0554de4 r6:e8441000 r5:e80fe868 r4:e80fe89c
[ 1081.205749] [<c0518c00>] (mutex_lock+0x0/0x7c) from [<c03650c4>] (show_product+0x28/0x50)
[ 1081.205871] r4:e80fe89c r3:c036509c
[ 1081.206695] [<c036509c>] (show_product+0x0/0x50) from [<c02fd678>] (dev_attr_show+0x30/0x54)
[ 1081.206817] r6:e8bc5f70 r5:e8537340 r4:c07b8240 r3:c036509c
[ 1081.208099] [<c02fd648>] (dev_attr_show+0x0/0x54) from [<c0153e4c>] (sysfs_read_file+0xc4/0x14c)
[ 1081.208190] r5:e8537340 r4:e84a7880
[ 1081.208496] [<c0153d88>] (sysfs_read_file+0x0/0x14c) from [<c00f80ec>] (vfs_read+0xc0/0x13c)
[ 1081.208618] [<c00f802c>] (vfs_read+0x0/0x13c) from [<c00f81b4>] (sys_read+0x4c/0x78)
[ 1081.208740] r8:00000000 r7:00000003 r6:00001000 r5:bece3304 r4:e8a56b40
[ 1081.209320] [<c00f8168>] (sys_read+0x0/0x78) from [<c000e200>] (ret_fast_syscall+0x0/0x30)
[ 1081.209350] r9:e8bc4000 r8:c000e468 r6:b6fe5920 r5:bece3304 r4:b6fea9ed
This happens with Ubuntu 12.04 armhf, kernel 3.4.23, Variscite SOM4460
We have 2 versions of firmware of modem and both versions resulting such bug.
Is this udev bug or may be ehci-omap driver?
WBR,