linux-kernel - Re: [PATCH v2] drm/bridge: anx7625: Drop device lock before drm_helper_hpd_irq

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <169018660964.606978.4469347765082724733.b4-ty@kernel.org>
Date:   Mon, 24 Jul 2023 10:16:56 +0200
From:   Robert Foss <rfoss@...nel.org>
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        Xin Ji <xji@...logixsemi.com>,
        Chen-Yu Tsai <wenst@...omium.org>,
        Andrzej Hajda <andrzej.hajda@...el.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Nícolas F . R . A . Prado 
        <nfraprado@...labora.com>, Jonas Karlman <jonas@...boo.se>
Cc:     Robert Foss <rfoss@...nel.org>, dri-devel@...ts.freedesktop.org,
        Daniel Vetter <daniel@...ll.ch>, linux-kernel@...r.kernel.org,
        David Airlie <airlied@...il.com>
Subject: Re: [PATCH v2] drm/bridge: anx7625: Drop device lock before drm_helper_hpd_irq_event()

On Mon, 10 Jul 2023 16:59:21 +0800, Chen-Yu Tsai wrote:
> The device lock is used to serialize the low level power sequencing
> operations. Since drm_helper_hpd_irq_event() could end up calling
> .atomic_enable, which also calls power sequencing functions through
> runtime PM, this results in a real deadlock. This was observed on an
> MT8192-based Chromebook's external display (with appropriate patches [1]
> and DT changes applied).
> 
> [...]

Applied, thanks!

[1/1] drm/bridge: anx7625: Drop device lock before drm_helper_hpd_irq_event()
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=f2cca20f1fa3



Rob