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Date:   Fri, 6 Aug 2021 15:47:21 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Loic Poulain <loic.poulain@linaro.org>
Cc:     davem@davemloft.net, netdev@vger.kernel.org,
        ryazanov.s.a@gmail.com, stable@vger.kernel.org
Subject: Re: [PATCH net-next] net: wwan: mhi_wwan_ctrl: Fix possible
 deadlock
Message-ID: <20210806154721.0333f733@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
In-Reply-To: <1628246109-27425-1-git-send-email-loic.poulain@linaro.org>
References: <1628246109-27425-1-git-send-email-loic.poulain@linaro.org>
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On Fri,  6 Aug 2021 12:35:09 +0200 Loic Poulain 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>

This is for net, right? Despite it's subject annotation?