From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
To: Jason-JH Lin <jason-jh.lin@mediatek.com>,
Chun-Kuang Hu <chunkuang.hu@kernel.org>,
David Airlie <airlied@gmail.com>
Cc: Xiandong Wang <xiandong.wang@mediatek.com>,
Philipp Zabel <p.zabel@pengutronix.de>,
Singo Chang <singo.chang@mediatek.com>,
Zhenxing Qin <zhenxing.qin@mediatek.com>,
linux-kernel@vger.kernel.org,
Yongqiang Niu <yongqiang.niu@mediatek.com>,
Project_Global_Chrome_Upstream_Group@mediatek.com,
Paul-PL Chen <paul-pl.chen@mediatek.com>,
Xavier Chang <xavier.chang@mediatek.com>,
Nancy Lin <nancy.lin@mediatek.com>,
linux-mediatek@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
Daniel Vetter <daniel@ffwll.ch>,
Sirius Wang <sirius.wang@mediatek.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
Jarried Lin <jarried.lin@mediatek.com>,
Chen-yu Tsai <wenst@chromium.org>
Subject: Re: [RESEND PATCH] drm/mediatek: Add error handling for old state CRTC in atomic_disable
Date: Tue, 29 Jul 2025 12:26:32 +0200 [thread overview]
Message-ID: <bba7ff19-8ce0-406d-b2a1-4489858fdb33@collabora.com> (raw)
In-Reply-To: <20250728025036.24953-1-jason-jh.lin@mediatek.com>
Il 28/07/25 04:48, Jason-JH Lin ha scritto:
> Introduce error handling to address an issue where, after a hotplug
> event, the cursor continues to update. This situation can lead to a
> kernel panic due to accessing the NULL `old_state->crtc`.
>
> E,g.
> Unable to handle kernel NULL pointer dereference at virtual address
> Call trace:
> mtk_crtc_plane_disable+0x24/0x140
> mtk_plane_atomic_update+0x8c/0xa8
> drm_atomic_helper_commit_planes+0x114/0x2c8
> drm_atomic_helper_commit_tail_rpm+0x4c/0x158
> commit_tail+0xa0/0x168
> drm_atomic_helper_commit+0x110/0x120
> drm_atomic_commit+0x8c/0xe0
> drm_atomic_helper_update_plane+0xd4/0x128
> __setplane_atomic+0xcc/0x110
> drm_mode_cursor_common+0x250/0x440
> drm_mode_cursor_ioctl+0x44/0x70
> drm_ioctl+0x264/0x5d8
> __arm64_sys_ioctl+0xd8/0x510
> invoke_syscall+0x6c/0xe0
> do_el0_svc+0x68/0xe8
> el0_svc+0x34/0x60
> el0t_64_sync_handler+0x1c/0xf8
> el0t_64_sync+0x180/0x188
>
> Adding NULL pointer checks to ensure stability by preventing operations
> on an invalid CRTC state.
>
> Fixes: d208261e9f7c ("drm/mediatek: Add wait_event_timeout when disabling plane")
> Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
next prev parent reply other threads:[~2025-07-29 10:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-28 2:48 [RESEND PATCH] drm/mediatek: Add error handling for old state CRTC in atomic_disable Jason-JH Lin
2025-07-29 10:26 ` AngeloGioacchino Del Regno [this message]
2025-07-30 1:12 ` CK Hu (胡俊光)
2025-08-13 23:55 ` Chun-Kuang Hu
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