From: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com
[ Upstream commit 3b8e19a0aa3933a785be9f1541afd8d398c4ec69 ]
In commit 41ca9caaae0b ("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 c91026a938c2 ("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: 41ca9caaae0b ("drm/mediatek: hdmi: Add check for CEA modes only") Fixes: c91026a938c2 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/mediatek/mtk_hdmi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c index 5838c44cbf6f0..3196189429bcf 100644 --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c @@ -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;