Re: [PATCH v3] firmware loader: fix hung task warning dump

From: Matt Fleming
Date: Tue Nov 25 2014 - 11:11:08 EST


On Tue, 18 Nov, at 10:56:59AM, Kweh Hock Leong wrote:
> From: "Kweh, Hock Leong" <hock.leong.kweh@xxxxxxxxx>
>
> When using request_firmware_nowait() with FW_ACTION_NOHOTPLUG param to
> expose user helper interface, if the user do not react immediately, after
> 120 seconds there will be a hung task warning message dumped as below:
>
> [ 3000.784235] INFO: task kworker/0:0:8259 blocked for more than 120 seconds.
> [ 3000.791281] Tainted: G E 3.16.0-rc1-yocto-standard #41
> [ 3000.798082] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> [ 3000.806072] kworker/0:0 D cd0075c8 0 8259 2 0x00000000
> [ 3000.812765] Workqueue: events request_firmware_work_func
> [ 3000.818253] cd375e18 00000046 0000000e cd0075c8 000000f0 cd40ea00 cd375fec 1b883e89
> [ 3000.826374] 0000026b cd40ea00 80000000 00000001 cd0075c8 00000000 cd375de4 c119917f
> [ 3000.834492] cd563360 cd375df4 c119a0ab cd563360 00000000 cd375e24 c119a1d6 00000000
> [ 3000.842616] Call Trace:
> [ 3000.845252] [<c119917f>] ? kernfs_next_descendant_post+0x3f/0x50
> [ 3000.851543] [<c119a0ab>] ? kernfs_activate+0x6b/0xc0
> [ 3000.856790] [<c119a1d6>] ? kernfs_add_one+0xd6/0x130
> [ 3000.862047] [<c15fdb02>] schedule+0x22/0x60
> [ 3000.866548] [<c15fd195>] schedule_timeout+0x175/0x1d0
> [ 3000.871887] [<c119b391>] ? __kernfs_create_file+0x71/0xa0
> [ 3000.877574] [<c119bb9a>] ? sysfs_add_file_mode_ns+0xaa/0x180
> [ 3000.883533] [<c15fe84f>] wait_for_completion+0x6f/0xb0
> [ 3000.888961] [<c1065200>] ? wake_up_process+0x40/0x40
> [ 3000.894219] [<c13cb600>] _request_firmware+0x750/0x9f0
> [ 3000.899666] [<c1382a7f>] ? n_tty_receive_buf2+0x1f/0x30
> [ 3000.905200] [<c13cba02>] request_firmware_work_func+0x22/0x50
> [ 3000.911235] [<c10550d2>] process_one_work+0x122/0x380
> [ 3000.916571] [<c1055859>] worker_thread+0xf9/0x470
> [ 3000.921555] [<c1055760>] ? create_and_start_worker+0x50/0x50
> [ 3000.927497] [<c1055760>] ? create_and_start_worker+0x50/0x50
> [ 3000.933448] [<c105a5ff>] kthread+0x9f/0xc0
> [ 3000.937850] [<c15ffd40>] ret_from_kernel_thread+0x20/0x30
> [ 3000.943548] [<c105a560>] ? kthread_worker_fn+0x100/0x100
>
> This patch change the wait_for_completion() function call to
> wait_for_completion_interruptible() function call for solving the issue.
>
> Cc: Matt Fleming <matt.fleming@xxxxxxxxx>
> Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@xxxxxxxxx>
> Acked-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Looks good to me. Who's going to pick this up? Ming, Greg, am I OK to
take this through the EFI tree or would you prefer to take it through
some other tree?

--
Matt Fleming, Intel Open Source Technology Center
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