Re: mxs-dcp: BUG: init/1 still has locks held!

[Alexander Shiyan]

Sun, 11 May 2014 16:57:57 -0300 от Fabio Estevam <festevam at gmail.com>:
> Hi,
> 
> Running linux-next 20140509 on a mx28evk I observe the following warning:
> 
> [    8.526613] Freeing unused kernel memory: 232K (c0683000 - c06bd000)
> starting pid 56, tty '': '/etc/rc.d/rcS'
> [    9.110314]
> [    9.111864] =====================================
> [    9.116603] [ BUG: init/1 still has locks held! ]
> [    9.121488] 3.15.0-rc4-next-20140509-00001-g319564e #1154 Not tainted
> [    9.128071] -------------------------------------
> [    9.132825] 1 lock held by init/1:
> [    9.136252]  #0:  (global_mutex){+.+.+.}, at: [<c0387d68>] mxs_dcp_probe+0x14
> [    9.144196]
> [    9.144196] stack backtrace:
> [    9.148888] CPU: 0 PID: 1 Comm: init Not tainted 3.15.0-rc4-next-20140509-004
> [    9.157610] [<c000da40>] (unwind_backtrace) from [<c000bda4>] (show_stack+0x)
> [    9.165595] [<c000bda4>] (show_stack) from [<c00153d4>] (do_fork+0x2c8/0x3cc)
> [    9.172921] [<c00153d4>] (do_fork) from [<c0015550>] (sys_vfork+0x20/0x2c)
> [    9.179973] [<c0015550>] (sys_vfork) from [<c0009580>] (ret_fast_syscall+0x0)
> Mounting /proc and /sys
> 
> Should we really use a global mutex here? What is a proper fix for this?

On my opinion mutex_lock/unlock should not be used in probe.
Try to remove this entirely.

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