net: wwan: mhi_wwan_ctrl: Fix possible deadlock

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Lockdep detected possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&mhiwwan->rx_lock);
                               local_irq_disable();
                               lock(&mhi_cntrl->pm_lock);
                               lock(&mhiwwan->rx_lock);
   <Interrupt>
     lock(&mhi_cntrl->pm_lock);

  *** DEADLOCK ***

To prevent this we need to disable the soft-interrupts when taking
the rx_lock.

Cc: stable@vger.kernel.org
Fixes: fa588eba63 ("net: Add Qcom WWAN control driver")
Reported-by: Thomas Perrot <thomas.perrot@bootlin.com>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

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Loic Poulain 2021-08-06 12:35:09 +02:00 • committed by David S. Miller

parent 47fac45600

commit 34737e1320

1 changed files with 6 additions and 6 deletions

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drivers/net/wwan/mhi_wwan_ctrl.c

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