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Re: [PATCH] irda: ali-ircc: Fix deadlock in ali_ircc_sir_change_speed()

From David Miller <davem@davemloft.net>
Newsgroups linux.kernel
Subject Re: [PATCH] irda: ali-ircc: Fix deadlock in ali_ircc_sir_change_speed()
Date 2015-09-12 01:20 +0200
Message-ID <q7FLR-7Un-43@gated-at.bofh.it> (permalink)
References <q7Ed3-5uE-7@gated-at.bofh.it>
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From: Alexey Khoroshilov <khoroshilov@ispras.ru>
Date: Sat, 12 Sep 2015 00:34:48 +0300

> ali_ircc_sir_change_speed() is always called with self->lock held,
> so acquiring the lock inside it leads to unavoidable deadlock.
> 
> Call graph:
> ali_ircc_sir_change_speed() is called from ali_ircc_change_speed()
>   ali_ircc_fir_hard_xmit() under spin_lock_irqsave(&self->lock, flags);
>   ali_ircc_sir_hard_xmit() under spin_lock_irqsave(&self->lock, flags);
>   ali_ircc_net_ioctl() under spin_lock_irqsave(&self->lock, flags);
>   ali_ircc_dma_xmit_complete()
>     ali_ircc_fir_interrupt()
>       ali_ircc_interrupt() under spin_lock(&self->lock);
>   ali_ircc_sir_write_wakeup()
>     ali_ircc_sir_interrupt()
>       ali_ircc_interrupt() under spin_lock(&self->lock);
> 
> The patch removes spin_lock/unlock from ali_ircc_sir_change_speed().
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>

Looks good, applied, thanks.
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[PATCH] irda: ali-ircc: Fix deadlock in ali_ircc_sir_change_speed() Alexey Khoroshilov <khoroshilov@ispras.ru> - 2015-09-11 23:40 +0200
  Re: [PATCH] irda: ali-ircc: Fix deadlock in  ali_ircc_sir_change_speed() David Miller <davem@davemloft.net> - 2015-09-12 01:20 +0200

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