Re: [PATCH net-next] net: wwan: mhi_wwan_ctrl: Fix possible deadlock

On Fri, Aug 6, 2021 at 1:24 PM Loic Poulain loic.poulain@linaro.org wrote:

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: fa588eba632d ("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