<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu/drm/mediatek, branch linux-6.13.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/mediatek: mtk_dpi: Explicitly manage TVD clock in power on/off</title>
<updated>2025-04-20T08:17:51+00:00</updated>
<author>
<name>AngeloGioacchino Del Regno</name>
<email>angelogioacchino.delregno@collabora.com</email>
</author>
<published>2025-02-17T15:48:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0e2d4197eadc145ba143d0d2bc0a966911a95a6b'/>
<id>0e2d4197eadc145ba143d0d2bc0a966911a95a6b</id>
<content type='text'>
[ Upstream commit 473c33f5ce651365468503c76f33158aaa1c7dd2 ]

In preparation for adding support for MT8195's HDMI reserved
DPI, add calls to clk_prepare_enable() / clk_disable_unprepare()
for the TVD clock: in this particular case, the aforementioned
clock is not (and cannot be) parented to neither pixel or engine
clocks hence it won't get enabled automatically by the clock
framework.

Please note that on all of the currently supported MediaTek
platforms, the TVD clock is always a parent of either pixel or
engine clocks, and this means that the common clock framework
is already enabling this clock before the children.
On such platforms, this commit will only increase the refcount
of the TVD clock without any functional change.

Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250217154836.108895-10-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 473c33f5ce651365468503c76f33158aaa1c7dd2 ]

In preparation for adding support for MT8195's HDMI reserved
DPI, add calls to clk_prepare_enable() / clk_disable_unprepare()
for the TVD clock: in this particular case, the aforementioned
clock is not (and cannot be) parented to neither pixel or engine
clocks hence it won't get enabled automatically by the clock
framework.

Please note that on all of the currently supported MediaTek
platforms, the TVD clock is always a parent of either pixel or
engine clocks, and this means that the common clock framework
is already enabling this clock before the children.
On such platforms, this commit will only increase the refcount
of the TVD clock without any functional change.

Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250217154836.108895-10-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: mtk_dpi: Move the input_2p_en bit to platform data</title>
<updated>2025-04-20T08:17:50+00:00</updated>
<author>
<name>AngeloGioacchino Del Regno</name>
<email>angelogioacchino.delregno@collabora.com</email>
</author>
<published>2025-02-17T15:47:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=04e974fbd20cea445957f38e1f132475c1abaae8'/>
<id>04e974fbd20cea445957f38e1f132475c1abaae8</id>
<content type='text'>
[ Upstream commit c90876a695dd83e76680b88b40067275a5982811 ]

In preparation for adding support for MT8195's HDMI reserved DPI
instance, move the input_2p_en bit for DP_INTF to platform data.

While at it, remove the input_2pixel member from platform data as
having this bit implies that the 2pixel feature must be enabled.

Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250217154836.108895-7-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c90876a695dd83e76680b88b40067275a5982811 ]

In preparation for adding support for MT8195's HDMI reserved DPI
instance, move the input_2p_en bit for DP_INTF to platform data.

While at it, remove the input_2pixel member from platform data as
having this bit implies that the 2pixel feature must be enabled.

Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250217154836.108895-7-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: dsi: fix error codes in mtk_dsi_host_transfer()</title>
<updated>2025-04-10T12:41:38+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@linaro.org</email>
</author>
<published>2025-01-08T09:35:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d3fc02db9bdb89a554e1b687df72d1d2b5c4536d'/>
<id>d3fc02db9bdb89a554e1b687df72d1d2b5c4536d</id>
<content type='text'>
[ Upstream commit dcb166ee43c3d594e7b73a24f6e8cf5663eeff2c ]

There is a type bug because the return statement:

        return ret &lt; 0 ? ret : recv_cnt;

The issue is that ret is an int, recv_cnt is a u32 and the function
returns ssize_t, which is a signed long.  The way that the type promotion
works is that the negative error codes are first cast to u32 and then
to signed long.  The error codes end up being positive instead of
negative and the callers treat them as success.

Fixes: 81cc7e51c4f1 ("drm/mediatek: Allow commands to be sent during video mode")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/r/202412210801.iADw0oIH-lkp@intel.com/
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Mattijs Korpershoek &lt;mkorpershoek@baylibre.com&gt;
Reviewed-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/b754a408-4f39-4e37-b52d-7706c132e27f@stanley.mountain/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit dcb166ee43c3d594e7b73a24f6e8cf5663eeff2c ]

There is a type bug because the return statement:

        return ret &lt; 0 ? ret : recv_cnt;

The issue is that ret is an int, recv_cnt is a u32 and the function
returns ssize_t, which is a signed long.  The way that the type promotion
works is that the negative error codes are first cast to u32 and then
to signed long.  The error codes end up being positive instead of
negative and the callers treat them as success.

Fixes: 81cc7e51c4f1 ("drm/mediatek: Allow commands to be sent during video mode")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/r/202412210801.iADw0oIH-lkp@intel.com/
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Mattijs Korpershoek &lt;mkorpershoek@baylibre.com&gt;
Reviewed-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/b754a408-4f39-4e37-b52d-7706c132e27f@stanley.mountain/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: dp: drm_err =&gt; dev_err in HPD path to avoid NULL ptr</title>
<updated>2025-04-10T12:41:38+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2025-01-16T17:42:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2fda391ef7a701748abd7fa32232981b522c1e07'/>
<id>2fda391ef7a701748abd7fa32232981b522c1e07</id>
<content type='text'>
[ Upstream commit 106a6de46cf4887d535018185ec528ce822d6d84 ]

The function mtk_dp_wait_hpd_asserted() may be called before the
`mtk_dp-&gt;drm_dev` pointer is assigned in mtk_dp_bridge_attach().
Specifically it can be called via this callpath:
 - mtk_edp_wait_hpd_asserted
 - [panel probe]
 - dp_aux_ep_probe

Using "drm" level prints anywhere in this callpath causes a NULL
pointer dereference. Change the error message directly in
mtk_dp_wait_hpd_asserted() to dev_err() to avoid this. Also change the
error messages in mtk_dp_parse_capabilities(), which is called by
mtk_dp_wait_hpd_asserted().

While touching these prints, also add the error code to them to make
future debugging easier.

Fixes: 7eacba9a083b ("drm/mediatek: dp: Add .wait_hpd_asserted() for AUX bus")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250116094249.1.I29b0b621abb613ddc70ab4996426a3909e1aa75f@changeid/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 106a6de46cf4887d535018185ec528ce822d6d84 ]

The function mtk_dp_wait_hpd_asserted() may be called before the
`mtk_dp-&gt;drm_dev` pointer is assigned in mtk_dp_bridge_attach().
Specifically it can be called via this callpath:
 - mtk_edp_wait_hpd_asserted
 - [panel probe]
 - dp_aux_ep_probe

Using "drm" level prints anywhere in this callpath causes a NULL
pointer dereference. Change the error message directly in
mtk_dp_wait_hpd_asserted() to dev_err() to avoid this. Also change the
error messages in mtk_dp_parse_capabilities(), which is called by
mtk_dp_wait_hpd_asserted().

While touching these prints, also add the error code to them to make
future debugging easier.

Fixes: 7eacba9a083b ("drm/mediatek: dp: Add .wait_hpd_asserted() for AUX bus")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250116094249.1.I29b0b621abb613ddc70ab4996426a3909e1aa75f@changeid/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: Fix config_updating flag never false when no mbox channel</title>
<updated>2025-04-10T12:41:38+00:00</updated>
<author>
<name>Jason-JH Lin</name>
<email>jason-jh.lin@mediatek.com</email>
</author>
<published>2025-02-24T05:12:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6b457654c945d354bb9b18d80a6c5cd1523326c8'/>
<id>6b457654c945d354bb9b18d80a6c5cd1523326c8</id>
<content type='text'>
[ Upstream commit 4ba973c8bad04d59fd4efa62512f4d9cee131714 ]

When CONFIG_MTK_CMDQ is enabled, if the display is controlled by the CPU
while other hardware is controlled by the GCE, the display will encounter
a mbox request channel failure.
However, it will still enter the CONFIG_MTK_CMDQ statement, causing the
config_updating flag to never be set to false. As a result, no page flip
event is sent back to user space, and the screen does not update.

Fixes: da03801ad08f ("drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()")
Signed-off-by: Jason-JH Lin &lt;jason-jh.lin@mediatek.com&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250224051301.3538484-1-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4ba973c8bad04d59fd4efa62512f4d9cee131714 ]

When CONFIG_MTK_CMDQ is enabled, if the display is controlled by the CPU
while other hardware is controlled by the GCE, the display will encounter
a mbox request channel failure.
However, it will still enter the CONFIG_MTK_CMDQ statement, causing the
config_updating flag to never be set to false. As a result, no page flip
event is sent back to user space, and the screen does not update.

Fixes: da03801ad08f ("drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()")
Signed-off-by: Jason-JH Lin &lt;jason-jh.lin@mediatek.com&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20250224051301.3538484-1-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: mtk_hdmi: Fix typo for aud_sampe_size member</title>
<updated>2025-04-10T12:41:36+00:00</updated>
<author>
<name>AngeloGioacchino Del Regno</name>
<email>angelogioacchino.delregno@collabora.com</email>
</author>
<published>2025-02-17T15:48:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3b7d250e50e24a3c6d40c592c43d4994ff04f50d'/>
<id>3b7d250e50e24a3c6d40c592c43d4994ff04f50d</id>
<content type='text'>
[ Upstream commit 72fcb88e7bbc053ed4fc74cebb0315b98a0f20c3 ]

Rename member aud_sampe_size of struct hdmi_audio_param to
aud_sample_size to fix a typo and enhance readability.

This commit brings no functional changes.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20250217154836.108895-20-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 72fcb88e7bbc053ed4fc74cebb0315b98a0f20c3 ]

Rename member aud_sampe_size of struct hdmi_audio_param to
aud_sample_size to fix a typo and enhance readability.

This commit brings no functional changes.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20250217154836.108895-20-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: mtk_hdmi: Unregister audio platform device on failure</title>
<updated>2025-04-10T12:41:36+00:00</updated>
<author>
<name>AngeloGioacchino Del Regno</name>
<email>angelogioacchino.delregno@collabora.com</email>
</author>
<published>2025-02-17T15:48:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ab81a0bc8d4fca13fd349106b397bf728639a2ab'/>
<id>ab81a0bc8d4fca13fd349106b397bf728639a2ab</id>
<content type='text'>
[ Upstream commit 0be123cafc06eed0fd1227166a66e786434b0c50 ]

The probe function of this driver may fail after registering the
audio platform device: in that case, the state is not getting
cleaned up, leaving this device registered.

Adding up to the mix, should the probe function of this driver
return a probe deferral for N times, we're registering up to N
audio platform devices and, again, never freeing them up.

To fix this, add a pointer to the audio platform device in the
mtk_hdmi structure, and add a devm action to unregister it upon
driver removal or probe failure.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20250217154836.108895-18-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0be123cafc06eed0fd1227166a66e786434b0c50 ]

The probe function of this driver may fail after registering the
audio platform device: in that case, the state is not getting
cleaned up, leaving this device registered.

Adding up to the mix, should the probe function of this driver
return a probe deferral for N times, we're registering up to N
audio platform devices and, again, never freeing them up.

To fix this, add a pointer to the audio platform device in the
mtk_hdmi structure, and add a devm action to unregister it upon
driver removal or probe failure.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20250217154836.108895-18-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mediatek-drm-fixes-20250104' of https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux into drm-fixes</title>
<updated>2025-01-10T06:57:59+00:00</updated>
<author>
<name>Dave Airlie</name>
<email>airlied@redhat.com</email>
</author>
<published>2025-01-10T06:57:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fddb4fd91a955636baa451fe82ad0266f55c7ede'/>
<id>fddb4fd91a955636baa451fe82ad0266f55c7ede</id>
<content type='text'>
Mediatek DRM Fixes - 20250104

1. Revert "drm/mediatek: dsi: Correct calculation formula of PHY Timing"
2. Set private-&gt;all_drm_private[i]-&gt;drm to NULL if mtk_drm_bind returns err
3. Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()
4. Only touch DISP_REG_OVL_PITCH_MSB if AFBC is supported
5. Add support for 180-degree rotation in the display driver
6. Stop selecting foreign drivers
7. Revert "drm/mediatek: Switch to for_each_child_of_node_scoped()"
8. Fix YCbCr422 color format issue for DP
9. Fix mode valid issue for dp
10. dp: Reference common DAI properties
11. dsi: Add registers to pdata to fix MT8186/MT8188
12. Remove unneeded semicolon
13. Add return value check when reading DPCD
14. Initialize pointer in mtk_drm_of_ddp_path_build_one()

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;

From: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250104124227.45505-1-chunkuang.hu@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Mediatek DRM Fixes - 20250104

1. Revert "drm/mediatek: dsi: Correct calculation formula of PHY Timing"
2. Set private-&gt;all_drm_private[i]-&gt;drm to NULL if mtk_drm_bind returns err
3. Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()
4. Only touch DISP_REG_OVL_PITCH_MSB if AFBC is supported
5. Add support for 180-degree rotation in the display driver
6. Stop selecting foreign drivers
7. Revert "drm/mediatek: Switch to for_each_child_of_node_scoped()"
8. Fix YCbCr422 color format issue for DP
9. Fix mode valid issue for dp
10. dp: Reference common DAI properties
11. dsi: Add registers to pdata to fix MT8186/MT8188
12. Remove unneeded semicolon
13. Add return value check when reading DPCD
14. Initialize pointer in mtk_drm_of_ddp_path_build_one()

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;

From: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250104124227.45505-1-chunkuang.hu@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: Initialize pointer in mtk_drm_of_ddp_path_build_one()</title>
<updated>2025-01-04T12:15:19+00:00</updated>
<author>
<name>AngeloGioacchino Del Regno</name>
<email>angelogioacchino.delregno@collabora.com</email>
</author>
<published>2024-11-12T10:50:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f563dd9ca6cb6ed52c5fb6e4285d1ef26cfa7e8a'/>
<id>f563dd9ca6cb6ed52c5fb6e4285d1ef26cfa7e8a</id>
<content type='text'>
The struct device_node *next pointer is not initialized, and it is
used in an error path in which it may have never been modified by
function mtk_drm_of_get_ddp_ep_cid().

Since the error path is relying on that pointer being NULL for the
OVL Adaptor and/or invalid component check and since said pointer
is being used in prints for %pOF, in the case that it points to a
bogus address, the print may cause a KP.

To resolve that, initialize the *next pointer to NULL before usage.

Fixes: 4c932840db1d ("drm/mediatek: Implement OF graphs support for display paths")
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/dri-devel/633f3c6d-d09f-447c-95f1-dfb4114c50e6@stanley.mountain/
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Reviewed-by: Alexandre Mergnat &lt;amergnat@baylibre.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241112105030.93337-1-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The struct device_node *next pointer is not initialized, and it is
used in an error path in which it may have never been modified by
function mtk_drm_of_get_ddp_ep_cid().

Since the error path is relying on that pointer being NULL for the
OVL Adaptor and/or invalid component check and since said pointer
is being used in prints for %pOF, in the case that it points to a
bogus address, the print may cause a KP.

To resolve that, initialize the *next pointer to NULL before usage.

Fixes: 4c932840db1d ("drm/mediatek: Implement OF graphs support for display paths")
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/dri-devel/633f3c6d-d09f-447c-95f1-dfb4114c50e6@stanley.mountain/
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Reviewed-by: CK Hu &lt;ck.hu@mediatek.com&gt;
Reviewed-by: Alexandre Mergnat &lt;amergnat@baylibre.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241112105030.93337-1-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mediatek: Add return value check when reading DPCD</title>
<updated>2025-01-04T12:15:08+00:00</updated>
<author>
<name>Liankun Yang</name>
<email>liankun.yang@mediatek.com</email>
</author>
<published>2024-12-18T11:34:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=522908140645865dc3e2fac70fd3b28834dfa7be'/>
<id>522908140645865dc3e2fac70fd3b28834dfa7be</id>
<content type='text'>
Check the return value of drm_dp_dpcd_readb() to confirm that
AUX communication is successful. To simplify the code, replace
drm_dp_dpcd_readb() and DP_GET_SINK_COUNT() with drm_dp_read_sink_count().

Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Liankun Yang &lt;liankun.yang@mediatek.com&gt;
Reviewed-by: Guillaume Ranquet &lt;granquet@baylibre.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241218113448.2992-1-liankun.yang@mediatek.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Check the return value of drm_dp_dpcd_readb() to confirm that
AUX communication is successful. To simplify the code, replace
drm_dp_dpcd_readb() and DP_GET_SINK_COUNT() with drm_dp_read_sink_count().

Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Liankun Yang &lt;liankun.yang@mediatek.com&gt;
Reviewed-by: Guillaume Ranquet &lt;granquet@baylibre.com&gt;
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241218113448.2992-1-liankun.yang@mediatek.com/
Signed-off-by: Chun-Kuang Hu &lt;chunkuang.hu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
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