Re: [PATCH] usb otg: use atomic notifier instead of blocking notifier

[Mian Yousaf Kaukab]

On 01/19/2011 10:20 AM, Yang Ruirui wrote:
> following bug happens with meego 2.6.35 kernel on nokia n900:
>
> [   28.693756] BUG: sleeping function called from invalid context at kernel/rwsem.c:21
> [   28.693786] in_atomic(): 1, irqs_disabled(): 128, pid: 706, name: udisks-part-id
> [   28.693817] 1 lock held by udisks-part-id/706:
> [   28.693817]  #0:  (&(&musb->lock)->rlock){-.-...}, at: [<c0278590>] musb_g_disconnect+0x90/0x148
> [   28.693908] irq event stamp: 1169
> [   28.693908] hardirqs last  enabled at (1168): [<c00c4b3c>] kmem_cache_alloc+0xd0/0x128
> [   28.693969] hardirqs last disabled at (1169): [<c002da34>] __irq_svc+0x34/0xb4
> [   28.694000] softirqs last  enabled at (0): [<c0054bcc>] copy_process+0x304/0xe18
> [   28.694030] softirqs last disabled at (0): [<(null)>] (null)
> [   28.694091] [<c00326a0>] (unwind_backtrace+0x0/0xec) from [<c037e6b0>] (down_read+0x20/0x5c)
> [   28.694152] [<c037e6b0>] (down_read+0x20/0x5c) from [<c0070770>] (__blocking_notifier_call_chain+0x2c/0x5c)
> [   28.694183] [<c0070770>] (__blocking_notifier_call_chain+0x2c/0x5c) from [<c00707b4>] (blocking_notifier_call_chain+0x14/0x18)
> [   28.694213] [<c00707b4>] (blocking_notifier_call_chain+0x14/0x18) from [<c02784d8>] (musb_gadget_vbus_draw+0x38/0x60)
> [   28.694274] [<c02784d8>] (musb_gadget_vbus_draw+0x38/0x60) from [<c0276d10>] (musb_interrupt+0xb08/0xcb0)
> [   28.694305] [<c0276d10>] (musb_interrupt+0xb08/0xcb0) from [<c0276f08>] (generic_interrupt+0x50/0x68)
> [   28.694335] [<c0276f08>] (generic_interrupt+0x50/0x68) from [<c008fcf4>] (handle_IRQ_event+0x24/0xe8)
> [   28.694396] [<c008fcf4>] (handle_IRQ_event+0x24/0xe8) from [<c0091924>] (handle_level_irq+0xac/0x128)
> [   28.694427] [<c0091924>] (handle_level_irq+0xac/0x128) from [<c002d070>] (asm_do_IRQ+0x70/0x90)
> [   28.694458] [<c002d070>] (asm_do_IRQ+0x70/0x90) from [<c002da4c>] (__irq_svc+0x4c/0xb4)
> [   28.694488] Exception stack(0xcd835ed0 to 0xcd835f18)
> [   28.694519] 5ec0:                                     cfc0a240 c8282000 0000006b 0000006b
> [   28.694549] 5ee0: cfc0a240 0000041a 00001000 00000000 c8282000 cd834000 c8282000 be80c464
> [   28.694580] 5f00: 00000c1e cd835f18 c00c333c c00c297c 80000013 ffffffff
> [   28.694610] [<c002da4c>] (__irq_svc+0x4c/0xb4) from [<c00c297c>] (check_poison_obj+0x24/0x194)
> [   28.694641] [<c00c297c>] (check_poison_obj+0x24/0x194) from [<c00c333c>] (cache_alloc_debugcheck_after+0x28/0x188)
> [   28.694671] [<c00c333c>] (cache_alloc_debugcheck_after+0x28/0x188) from [<c00c4b54>] (kmem_cache_alloc+0xe8/0x128)
> [   28.694732] [<c00c4b54>] (kmem_cache_alloc+0xe8/0x128) from [<c00d79dc>] (getname+0x18/0xcc)
> [   28.694763] [<c00d79dc>] (getname+0x18/0xcc) from [<c00cbca8>] (do_sys_open+0x18/0x10c)
> [   28.694793] [<c00cbca8>] (do_sys_open+0x18/0x10c) from [<c002df40>] (ret_fast_syscall+0x0/0x3c)
> [   28.694854]
> [   28.694854] =================================
> [   28.709014] [ INFO: inconsistent lock state ]
> [   28.717254] 2.6.35.96.5-adaptation-n900 #1
> [   28.725128] ---------------------------------
> [   28.733123] inconsistent {HARDIRQ-ON-W} ->  {IN-HARDIRQ-R} usage.
> [   28.742980] udisks-part-id/706 [HC1[1]:SC0[0]:HE0:SE1] takes:
> [   28.752441]  (&(&twl->otg.notifier)->rwsem){+-+...}, at: [<c0070770>] __blocking_notifier_call_chain+0x2c/0x5c
> [   28.769836] {HARDIRQ-ON-W} state was registered at:
> [   28.778320]   [<c007c1dc>] __lock_acquire+0x618/0x1730
> [   28.787109]   [<c007d354>] lock_acquire+0x60/0x74
> [   28.795227]   [<c037e67c>] down_write+0x48/0x5c
> [   28.803131]   [<c00708a8>] blocking_notifier_chain_register+0x30/0x54
> [   28.812896]   [<bf0da9f8>] isp1704_charger_probe+0x268/0x39c [isp1704_charger]
> [   28.823394]   [<c0239410>] platform_drv_probe+0x18/0x1c
> [   28.831787]   [<c02385c8>] driver_probe_device+0xa8/0x158
> [   28.840332]   [<c02386e0>] __driver_attach+0x68/0x8c
> [   28.848510]   [<c0237e68>] bus_for_each_dev+0x44/0x74
> [   28.856689]   [<c02377c8>] bus_add_driver+0x9c/0x20c
> [   28.864746]   [<c02389b0>] driver_register+0xa8/0x138
> [   28.872955]   [<c002d340>] do_one_initcall+0x58/0x1ac
> [   28.881134]   [<c0085cdc>] sys_init_module+0x90/0x1b0
> [   28.889343]   [<c002df40>] ret_fast_syscall+0x0/0x3c
> [   28.897491] irq event stamp: 1169
> [   28.904083] hardirqs last  enabled at (1168): [<c00c4b3c>] kmem_cache_alloc+0xd0/0x128
> [   28.915557] hardirqs last disabled at (1169): [<c002da34>] __irq_svc+0x34/0xb4
> [   28.926239] softirqs last  enabled at (0): [<c0054bcc>] copy_process+0x304/0xe18
> [   28.937194] softirqs last disabled at (0): [<(null)>] (null)
> [   28.946258]
> [   28.946258] other info that might help us debug this:
> [   28.959381] 1 lock held by udisks-part-id/706:
> [   28.967163]  #0:  (&(&musb->lock)->rlock){-.-...}, at: [<c0278590>] musb_g_disconnect+0x90/0x148
> [   28.979705]
> [   28.979705] stack backtrace:
> [   28.990997] [<c00326a0>] (unwind_backtrace+0x0/0xec) from [<c007a39c>] (print_usage_bug+0x170/0x1b4)
> [   29.007293] [<c007a39c>] (print_usage_bug+0x170/0x1b4) from [<c007a738>] (mark_lock+0x358/0x628)
> [   29.019836] [<c007a738>] (mark_lock+0x358/0x628) from [<c007c118>] (__lock_acquire+0x554/0x1730)
> [   29.032409] [<c007c118>] (__lock_acquire+0x554/0x1730) from [<c007d354>] (lock_acquire+0x60/0x74)
> [   29.045166] [<c007d354>] (lock_acquire+0x60/0x74) from [<c037e6d8>] (down_read+0x48/0x5c)
> [   29.057250] [<c037e6d8>] (down_read+0x48/0x5c) from [<c0070770>] (__blocking_notifier_call_chain+0x2c/0x5c)
> [   29.074920] [<c0070770>] (__blocking_notifier_call_chain+0x2c/0x5c) from [<c00707b4>] (blocking_notifier_call_chain+0x14/0x18)
> [   29.094573] [<c00707b4>] (blocking_notifier_call_chain+0x14/0x18) from [<c02784d8>] (musb_gadget_vbus_draw+0x38/0x60)
> [   29.113891] [<c02784d8>] (musb_gadget_vbus_draw+0x38/0x60) from [<c0276d10>] (musb_interrupt+0xb08/0xcb0)
> [   29.132629] [<c0276d10>] (musb_interrupt+0xb08/0xcb0) from [<c0276f08>] (generic_interrupt+0x50/0x68)
> [   29.151580] [<c0276f08>] (generic_interrupt+0x50/0x68) from [<c008fcf4>] (handle_IRQ_event+0x24/0xe8)
> [   29.171081] [<c008fcf4>] (handle_IRQ_event+0x24/0xe8) from [<c0091924>] (handle_level_irq+0xac/0x128)
> [   29.190948] [<c0091924>] (handle_level_irq+0xac/0x128) from [<c002d070>] (asm_do_IRQ+0x70/0x90)
> [   29.205291] [<c002d070>] (asm_do_IRQ+0x70/0x90) from [<c002da4c>] (__irq_svc+0x4c/0xb4)
> [   29.218963] Exception stack(0xcd835ed0 to 0xcd835f18)
> [   29.229644] 5ec0:                                     cfc0a240 c8282000 0000006b 0000006b
> [   29.243591] 5ee0: cfc0a240 0000041a 00001000 00000000 c8282000 cd834000 c8282000 be80c464
> [   29.257629] 5f00: 00000c1e cd835f18 c00c333c c00c297c 80000013 ffffffff
> [   29.270111] [<c002da4c>] (__irq_svc+0x4c/0xb4) from [<c00c297c>] (check_poison_obj+0x24/0x194)
> [   29.284637] [<c00c297c>] (check_poison_obj+0x24/0x194) from [<c00c333c>] (cache_alloc_debugcheck_after+0x28/0x188)
> [   29.306732] [<c00c333c>] (cache_alloc_debugcheck_after+0x28/0x188) from [<c00c4b54>] (kmem_cache_alloc+0xe8/0x128)
> [   29.329071] [<c00c4b54>] (kmem_cache_alloc+0xe8/0x128) from [<c00d79dc>] (getname+0x18/0xcc)
> [   29.343597] [<c00d79dc>] (getname+0x18/0xcc) from [<c00cbca8>] (do_sys_open+0x18/0x10c)
> [   29.357696] [<c00cbca8>] (do_sys_open+0x18/0x10c) from [<c002df40>] (ret_fast_syscall+0x0/0x3c)
>
> Actually the blocking notifier chain runs in process context, so not fit for use here.
>
> For mainline kernel there's such issue as well.
> Here fix this problem by changing to use atomic_notifier.
>
> Signed-off-by: Yang Ruirui<ruirui.r.yang@xxxxxxxxx>
>    

for ab8500-usb.c parts:

Acked-by: Mian Yousaf Kaukab<mian.yousaf.kaukab@xxxxxxxxxxxxxx>


--
Mian Yousaf Kaukab


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