| Message ID | 20211028074311.57842-1-angelogioacchino.delregno@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: hdmi: Perform NULL pointer check for mtk_hdmi_conf | expand |
Il 28/10/21 09:43, AngeloGioacchino Del Regno ha scritto: > 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> > --- > 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 5838c44cbf6f..3196189429bc 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; > Hello, friendly ping! Can I please get a review (or merge) of this commit? This is an important fix for a null pointer KP and restores HDMI functionality. Thanks, - Angelo
Hi, Angelo: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> 於 2021年12月13日 週一 下午6:02寫道： > > Il 28/10/21 09:43, AngeloGioacchino Del Regno ha scritto: > > 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> > > --- > > 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 5838c44cbf6f..3196189429bc 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; > > > > Hello, friendly ping! > > Can I please get a review (or merge) of this commit? > > This is an important fix for a null pointer KP and restores HDMI functionality. Applied to mediatek-drm-fixes [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes Regards, Chun-Kuang. > > Thanks, > - Angelo
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c index 5838c44cbf6f..3196189429bc 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;
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> --- drivers/gpu/drm/mediatek/mtk_hdmi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)