[PATCH v1 0/2] exynos_mct driver: fix irq allocation and cleanup

On Thu, Feb 13, 2014 at 10:31 PM, Tarek Dakhran [off-list ref] wrote:

Hi Tomasz,

On Thursday, February 13, 2014, Tomasz Figa [off-list ref] wrote:

quoted

Hi Tarek,

On 13.02.2014 04:08, Tarek Dakhran wrote:

quoted

exynos4_local_timer_setup called on the secondary cpu before
irqs are enabled. request_irq can sleep, which produces next warning:

on boot:
[    0.370000] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
[    0.370000] Setting up static identity map for 0x403b5700 - 0x403b5758
[    0.395000] CPU1: Booted secondary processor
[    0.395000] ------------[ cut here ]------------
[    0.395000] WARNING: CPU: 1 PID: 0 at kernel/locking/lockdep.c:2742
lockdep_trace_alloc+0xe0/0xfc()
[    0.395000] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
[    0.395000] Modules linked in:
[    0.395000] CPU: 1 PID: 0 Comm: swapper/1 Not tainted
3.14.0-rc2-00004-g0db95f4 #128
[    0.395000] [<c0014308>] (unwind_backtrace) from [<c0011690>]
(show_stack+0x10/0x14)
[    0.395000] [<c0011690>] (show_stack) from [<c03ae7d0>]
(dump_stack+0x6c/0xb8)
[    0.395000] [<c03ae7d0>] (dump_stack) from [<c001d504>]
(warn_slowpath_common+0x68/0x8c)
[    0.395000] [<c001d504>] (warn_slowpath_common) from [<c001d5bc>]
(warn_slowpath_fmt+0x30/0x40)
[    0.395000] [<c001d5bc>] (warn_slowpath_fmt) from [<c0059824>]
(lockdep_trace_alloc+0xe0/0xfc)
[    0.395000] [<c0059824>] (lockdep_trace_alloc) from [<c00bee24>]
(kmem_cache_alloc+0x24/0x160)
[    0.395000] [<c00bee24>] (kmem_cache_alloc) from [<c0068174>]
(request_threaded_irq+0x64/0x130)
[    0.395000] [<c0068174>] (request_threaded_irq) from [<c02efaf8>]
(exynos4_local_timer_setup+0xd0/0x124)
[    0.395000] [<c02efaf8>] (exynos4_local_timer_setup) from [<c02efc34>]
(exynos4_mct_cpu_notify+0x78/0xf0)
[    0.395000] [<c02efc34>] (exynos4_mct_cpu_notify) from [<c003d318>]
(notifier_call_chain+0x44/0x84)
[    0.395000] [<c003d318>] (notifier_call_chain) from [<c001d61c>]
(__cpu_notify+0x24/0x40)
[    0.395000] [<c001d61c>] (__cpu_notify) from [<c0013314>]
(secondary_start_kernel+0xe4/0x134)
[    0.395000] [<c0013314>] (secondary_start_kernel) from [<40008624>]
(0x40008624)
[    0.395000] ---[ end trace 347890460e745f50 ]---
[    0.420000] CPU1: update cpu_power 1024
[    0.420000] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001

on hotplug:
[  108.040000] CPU3: Booted secondary processor
[  108.040000] BUG: sleeping function called from invalid context at
mm/slub.c:965
[  108.040000] in_atomic(): 1, irqs_disabled(): 128, pid: 0, name:
swapper/3
[  108.040000] INFO: lockdep is turned off.
[  108.040000] irq event stamp: 0
[  108.040000] hardirqs last  enabled at (0): [<  (null)>]   (null)
[  108.040000] hardirqs last disabled at (0): [<c001b768>]
copy_process.part.2+0x2a4/0x12f4
[  108.040000] softirqs last  enabled at (0): [<c001b768>]
copy_process.part.2+0x2a4/0x12f4
[  108.040000] softirqs last disabled at (0): [<  (null)>]   (null)
[  108.040000] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G        W
3.14.0-rc2-00004-g0db95f4 #128
[  108.040000] [<c0014308>] (unwind_backtrace) from [<c0011690>]
(show_stack+0x10/0x14)
[  108.040000] [<c0011690>] (show_stack) from [<c03ae7d0>]
(dump_stack+0x6c/0xb8)
[  108.040000] [<c03ae7d0>] (dump_stack) from [<c00beed4>]
(kmem_cache_alloc+0xd4/0x160)
[  108.040000] [<c00beed4>] (kmem_cache_alloc) from [<c0068174>]
(request_threaded_irq+0x64/0x130)
[  108.040000] [<c0068174>] (request_threaded_irq) from [<c02efaf8>]
(exynos4_local_timer_setup+0xd0/0x124)
[  108.040000] [<c02efaf8>] (exynos4_local_timer_setup) from [<c02efc34>]
(exynos4_mct_cpu_notify+0x78/0xf0)
[  108.040000] [<c02efc34>] (exynos4_mct_cpu_notify) from [<c003d318>]
(notifier_call_chain+0x44/0x84)
[  108.040000] [<c003d318>] (notifier_call_chain) from [<c001d61c>]
(__cpu_notify+0x24/0x40)
[  108.040000] [<c001d61c>] (__cpu_notify) from [<c0013314>]
(secondary_start_kernel+0xe4/0x134)
[  108.040000] [<c0013314>] (secondary_start_kernel) from [<40008624>]
(0x40008624)

First patch fixes this problem by removing request_irq from
exynos4_local_timer_setup
Second removes non-dt stuff.

Tested on linux kernel v3.14-rc2.

It would be nice to say on which boards it has been tested. Let me check
this on our boards anyway.

Best regards,
Tomasz

Tested on smdk5410 reference board with lockdep enabled.
I think the problem will present on all boards due to call sleeping function
in irq_disabled context.

Best Regards,
    Tarek

Has anyone else tested this patches?
if yes, what is the result?


Best regards,
. Tarek