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drm/mediatek: hdmi: Perform NULL pointer check for mtk_hdmi_conf

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In commit 41ca9caaae
("drm/mediatek: hdmi: Add check for CEA modes only") a check
for CEA modes was added to function mtk_hdmi_bridge_mode_valid()
in order to address possible issues on MT8167;
moreover, with commit c91026a938
("drm/mediatek: hdmi: Add optional limit on maximal HDMI mode clock")
another similar check was introduced.

Unfortunately though, at the time of writing, MT8173 does not provide
any mtk_hdmi_conf structure and this is crashing the kernel with NULL
pointer upon entering mtk_hdmi_bridge_mode_valid(), which happens as
soon as a HDMI cable gets plugged in.

To fix this regression, add a NULL pointer check for hdmi->conf in the
said function, restoring HDMI functionality and avoiding NULL pointer
kernel panics.

Fixes: 41ca9caaae ("drm/mediatek: hdmi: Add check for CEA modes only")
Fixes: c91026a938 ("drm/mediatek: hdmi: Add optional limit on maximal HDMI mode clock")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
This commit is contained in:
AngeloGioacchino Del Regno 2021-10-28 09:43:11 +02:00 committed by Chun-Kuang Hu
parent fa55b7dcdc
commit 3b8e19a0aa
1 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/gpu/drm/mediatek/mtk_hdmi.c
View File

@ -1224,12 +1224,14 @@ static int mtk_hdmi_bridge_mode_valid(struct drm_bridge *bridge,
return MODE_BAD;
}
if (hdmi->conf->cea_modes_only && !drm_match_cea_mode(mode))
return MODE_BAD;
if (hdmi->conf) {
if (hdmi->conf->cea_modes_only && !drm_match_cea_mode(mode))
return MODE_BAD;
if (hdmi->conf->max_mode_clock &&
mode->clock > hdmi->conf->max_mode_clock)
return MODE_CLOCK_HIGH;
if (hdmi->conf->max_mode_clock &&
mode->clock > hdmi->conf->max_mode_clock)
return MODE_CLOCK_HIGH;
}
if (mode->clock < 27000)
return MODE_CLOCK_LOW;