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Message-ID: <2d419a7d1d10067760fcc553582e87fb3ca4a34a.camel@sipsolutions.net>
Subject: Re: [PATCH 5.12 regression fix] brcmfmac: p2p: Fix recently
 introduced deadlock issue
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Hans de Goede <hdegoede@redhat.com>,
        Arend van Spriel <aspriel@gmail.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        Chi-Hsien Lin <chi-hsien.lin@infineon.com>,
        Chung-hsien Hsu <chung-hsien.hsu@infineon.com>,
        Wright Feng <wright.feng@infineon.com>
Cc:     linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com,
        SHA-cyfmac-dev-list@infineon.com
Date:   Sat, 13 Mar 2021 16:22:50 +0100
In-Reply-To: <20210313143635.109154-1-hdegoede@redhat.com> (sfid-20210313_153800_338272_9A5AD47E)
References: <20210313143635.109154-1-hdegoede@redhat.com>
         (sfid-20210313_153800_338272_9A5AD47E)
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On Sat, 2021-03-13 at 15:36 +0100, Hans de Goede wrote:
> Commit a05829a7222e ("cfg80211: avoid holding the RTNL when calling the
> driver") replaced the rtnl_lock parameter passed to various brcmf
> functions with just lock, because since that commit it is not just
> about the rtnl_lock but also about the wiphy_lock .
> 
> During this search/replace the "if (!rtnl_locked)" check in brcmfmac/p2p.c
> was accidentally replaced with "if (locked)", dropping the inversion of
> the check. This causes the code to now call rtnl_lock() while already
> holding the lock, causing a deadlock.
> 
> Add back the "!" to the if-condition to fix this.

Ouch, sorry about that, and thanks for the fix!

johannes