Hi guys, I am trying to enable the CD-ROM on Freescale's i.MX25 PDK, 31 kernel, with the rt patch applied. But met the problem as below. I turned on most of the RT debug options. I went through the register_cdrom() function, and it does not seem to any problem. Has anyone met this before ? Any one can help ? ------------[ cut here ]------------ WARNING: at kernel/lockdep.c:2631 __lock_acquire+0x6cc/0x89c() Modules linked in: cdmm10(+) cdrom ehci_hcd [<c002561c>] (unwind_backtrace+0x0/0xd4) from [<c003aabc>] (warn_slowpath_common+0x4c/0x68) [<c003aabc>] (warn_slowpath_common+0x4c/0x68) from [<c005f25c>] (__lock_acquire+0x6cc/0x89c) [<c005f25c>] (__lock_acquire+0x6cc/0x89c) from [<c0060198>] (lock_acquire+0x5c/0x70) [<c0060198>] (lock_acquire+0x5c/0x70) from [<c0249aa0>] (_atomic_spin_lock_irqsave+0x4c/0x60) [<c0249aa0>] (_atomic_spin_lock_irqsave+0x4c/0x60) from [<c0248a6c>] (rt_mutex_slowlock+0x30/0x228) [<c0248a6c>] (rt_mutex_slowlock+0x30/0x228) from [<bf00ebf4>] (register_cdrom+0x224/0x28c [cdrom]) [<bf00ebf4>] (register_cdrom+0x224/0x28c [cdrom]) from [<bf026098>] (cdmm10_init+0x98/0x17c [cdmm10]) [<bf026098>] (cdmm10_init+0x98/0x17c [cdmm10]) from [<c0020300>] (do_one_initcall+0x58/0x1a8) [<c0020300>] (do_one_initcall+0x58/0x1a8) from [<c0068a5c>] (sys_init_module+0xc0/0x1d8) [<c0068a5c>] (sys_init_module+0xc0/0x1d8) from [<c0020e20>] (ret_fast_syscall+0x0/0x2c) ---[ end trace 6ec5129019052f27 ]--- Unable to handle kernel NULL pointer dereference at virtual address 00000030 pgd = c3054000 [00000030] *pgd=83bf2031, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT Modules linked in: cdmm10(+) cdrom ehci_hcd CPU: 0 Tainted: G W (2.6.31-209-g699787d-g7105196-dirty #9) PC is at task_blocks_on_rt_mutex+0xa8/0x1d0 LR is at __rt_mutex_adjust_prio+0xc/0x2c pc : [<c0064074>] lr : [<c0063814>] psr: 00000093 sp : c3025e30 ip : c3024000 fp : c3025ed0 r10: fffffff4 r9 : c38540e0 r8 : bf01668c r7 : 00000000 r6 : c3025eb4 r5 : bf016636 r4 : c385442c r3 : bf0166b0 r2 : 00000000 r1 : 00000076 r0 : 00000000 Flags: nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 0005317f Table: 83054000 DAC: 00000015 Process modprobe (pid: 500, stack limit = 0xc3024270) Stack: (0xc3025e30 to 0xc3026000) 5e20: 00000002 60000093 c3024000 00000000 5e40: 00000000 c3025eb4 c3024000 bf01668c 00000000 00000000 40000013 00000004 5e60: 00000000 c0248854 40000013 00000000 bf02304c 00000004 00000000 bf01668c 5e80: 00000000 bf02304c c3025eb4 40000013 00000000 c0248bbc 00000000 40000013 5ea0: 00000001 00000000 00000004 ffffffff 60000013 00000076 c3025eb8 c3025eb8 5ec0: c3025ec0 c3025ec0 00000000 00000000 00000076 c3025ed4 c3025ed4 c3025edc 5ee0: c3025edc 00000000 00000000 c38540e0 bf01668c 11111111 00000000 11111111 5f00: bf01695c bf022ecc bf022e2c bf01695c bf022e2c bf02304c c3024000 00000001 5f20: 00000002 bf00ebf4 c3bf4000 00000000 c0339e2c bf026098 00000002 bf02618c 5f40: 00000000 bf022f08 c0339e2c bf02617c 00000000 c0020300 c0249bc0 0000869e 5f60: bf022f08 00000000 0009eaf8 c0020fa4 00000000 bf022f08 00000000 0009eaf8 5f80: c0020fa4 c0068a5c 0000000c c0094564 0009eaf8 0000869e 0009e1a0 0009e498 5fa0: 00000080 c0020e20 0000869e 0009e1a0 0009eaf8 0000869e 0009e498 0009e3d8 5fc0: 0000869e 0009e1a0 0009e498 00000080 0009e3f8 0000006c 00000001 00000002 5fe0: be89b970 be89b960 00015a50 400dc320 20000010 0009eaf8 00000000 00000000 [<c0064074>] (task_blocks_on_rt_mutex+0xa8/0x1d0) from [<c0248854>] (__rt_mutex_slowlock+0xa4/0x100) [<c0248854>] (__rt_mutex_slowlock+0xa4/0x100) from [<c0248bbc>] (rt_mutex_slowlock+0x180/0x228) [<c0248bbc>] (rt_mutex_slowlock+0x180/0x228) from [<bf00ebf4>] (register_cdrom+0x224/0x28c [cdrom]) [<bf00ebf4>] (register_cdrom+0x224/0x28c [cdrom]) from [<bf026098>] (cdmm10_init+0x98/0x17c [cdmm10]) [<bf026098>] (cdmm10_init+0x98/0x17c [cdmm10]) from [<c0020300>] (do_one_initcall+0x58/0x1a8) [<c0020300>] (do_one_initcall+0x58/0x1a8) from [<c0068a5c>] (sys_init_module+0xc0/0x1d8) [<c0068a5c>] (sys_init_module+0xc0/0x1d8) from [<c0020e20>] (ret_fast_syscall+0x0/0x2c) Code: e286b01c 01a0a006 0a000006 e242a00c (e59a303c) ---[ end trace 6ec5129019052f28 ]--- Best Regards. William Lai -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html