Messages in this thread | | | Date | Wed, 4 Oct 2006 07:43:08 +0200 | From | Jarek Poplawski <> | Subject | Re: Problems with hard irq? (inconsistent lock state) |
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On 29-09-2006 13:45, Axel C. Voigt wrote: > > Hello all, > > today I received the following stack backtrace using debian-2.6.18 with our communications driver accessing a ACM device. This happened when removing (powering off and/or on) the mobile phone (nokia 6630) at /dev/ttyACMx > > Are someone able to get a hint for me? > > --schnipp-- > Sep 29 13:29:53 mcs70 kernel: > Sep 29 13:29:53 mcs70 kernel: ================================= > Sep 29 13:29:53 mcs70 kernel: [ INFO: inconsistent lock state ] > Sep 29 13:29:53 mcs70 kernel: --------------------------------- > Sep 29 13:29:53 mcs70 kernel: inconsistent {hardirq-on-W} -> {in-hardirq-W} usage. > Sep 29 13:29:53 mcs70 kernel: startDV24/3864 [HC1[1]:SC0[0]:HE0:SE1] takes: > Sep 29 13:29:53 mcs70 kernel: (&acm->read_lock){++..}, at: [<e08952d8>] acm_read_bulk+0x60/0xde [cdc_acm] > Sep 29 13:29:53 mcs70 kernel: {hardirq-on-W} state was registered at: > Sep 29 13:29:53 mcs70 kernel: [<c01321f3>] lock_acquire+0x56/0x73 > Sep 29 13:29:53 mcs70 kernel: [<c02ce42a>] _spin_lock+0x1a/0x25 > Sep 29 13:29:53 mcs70 kernel: [<e08953a8>] acm_rx_tasklet+0x52/0x2be [cdc_acm] > Sep 29 13:29:53 mcs70 kernel: [<c011f868>] tasklet_action+0x6d/0xd7 > Sep 29 13:29:53 mcs70 kernel: [<c011f526>] __do_softirq+0x79/0xf2 ... > Sep 29 13:29:53 mcs70 kernel: stack backtrace: > Sep 29 13:29:53 mcs70 kernel: [<c010376e>] show_trace+0x16/0x18 > Sep 29 13:29:53 mcs70 kernel: [<c010383c>] dump_stack+0x19/0x1b > Sep 29 13:29:53 mcs70 kernel: [<c0130ad8>] print_usage_bug+0x1e1/0x1eb > Sep 29 13:29:53 mcs70 kernel: [<c0130b86>] mark_lock+0xa4/0x4d9 > Sep 29 13:29:53 mcs70 kernel: [<c0131823>] __lock_acquire+0x41a/0x841 > Sep 29 13:29:53 mcs70 kernel: [<c01321f3>] lock_acquire+0x56/0x73 > Sep 29 13:29:53 mcs70 kernel: [<c02ce42a>] _spin_lock+0x1a/0x25 > Sep 29 13:29:53 mcs70 kernel: [<e08952d8>] acm_read_bulk+0x60/0xde [cdc_acm] ... > Sep 29 13:29:53 mcs70 kernel: [<c0104b26>] do_IRQ+0x4e/0x5f > Sep 29 13:29:53 mcs70 kernel: [<c0103339>] common_interrupt+0x25/0x2c ...
It looks in drivers/usb/class/cdc-acm.c acm_rx_tasklet could be preempted with acm->read_lock by acm_read_bulk which uses the same lock from hardirq context.
So probably spin_lock_irqsave is needed.
> Mit freundlichen Grüssen/ with kind regards, > > Axel C. Voigt
Serdecznie pozdrawiam/ cheers,
Jarek P. > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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