<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/gpu/drm/bridge, branch linux-6.0.y</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=linux-6.0.y</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=linux-6.0.y'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2022-12-31T12:25:50+00:00</updated>
<entry>
<title>drm/bridge: it6505: Initialize AUX channel in it6505_i2c_probe</title>
<updated>2022-12-31T12:25:50+00:00</updated>
<author>
<name>Pin-yen Lin</name>
<email>treapking@chromium.org</email>
</author>
<published>2022-10-13T11:04:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8ed8505803774fc3f36a432718036c21cc51e2ba'/>
<id>urn:sha1:8ed8505803774fc3f36a432718036c21cc51e2ba</id>
<content type='text'>
[ Upstream commit e577d4b13064c337b83fe7edecb3f34e87144821 ]

During device boot, the HPD interrupt could be triggered before the DRM
subsystem registers it6505 as a DRM bridge. In such cases, the driver
tries to access AUX channel and causes NULL pointer dereference.
Initializing the AUX channel earlier to prevent such error.

Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
Signed-off-by: Pin-yen Lin &lt;treapking@chromium.org&gt;
Reviewed-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20221013110411.1674359-2-treapking@chromium.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/bridge: adv7533: remove dynamic lane switching from adv7533 bridge</title>
<updated>2022-12-31T12:25:49+00:00</updated>
<author>
<name>Abhinav Kumar</name>
<email>quic_abhinavk@quicinc.com</email>
</author>
<published>2022-10-11T21:10:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8ccbb264d1e9c12ac75ffc453e9e1793750b8b0c'/>
<id>urn:sha1:8ccbb264d1e9c12ac75ffc453e9e1793750b8b0c</id>
<content type='text'>
[ Upstream commit 9a0cdcd6649b76f0b7ceec0e55b0a718321e34d3 ]

adv7533 bridge tries to dynamically switch lanes based on the
mode by detaching and attaching the mipi dsi device.

This approach is incorrect because this method of dynamic switch of
detaching and attaching the mipi dsi device also results in removing
and adding the component which is not necessary.

This approach is also prone to deadlocks. So for example, on the
db410c whenever this path is executed with lockdep enabled,
this results in a deadlock due to below ordering of locks.

-&gt; #1 (crtc_ww_class_acquire){+.+.}-{0:0}:
        lock_acquire+0x6c/0x90
        drm_modeset_acquire_init+0xf4/0x150
        drmm_mode_config_init+0x220/0x770
        msm_drm_bind+0x13c/0x654
        try_to_bring_up_aggregate_device+0x164/0x1d0
        __component_add+0xa8/0x174
        component_add+0x18/0x2c
        dsi_dev_attach+0x24/0x30
        dsi_host_attach+0x98/0x14c
        devm_mipi_dsi_attach+0x38/0xb0
        adv7533_attach_dsi+0x8c/0x110
        adv7511_probe+0x5a0/0x930
        i2c_device_probe+0x30c/0x350
        really_probe.part.0+0x9c/0x2b0
        __driver_probe_device+0x98/0x144
        driver_probe_device+0xac/0x14c
        __device_attach_driver+0xbc/0x124
        bus_for_each_drv+0x78/0xd0
        __device_attach+0xa8/0x1c0
        device_initial_probe+0x18/0x24
        bus_probe_device+0xa0/0xac
        deferred_probe_work_func+0x90/0xd0
        process_one_work+0x28c/0x6b0
        worker_thread+0x240/0x444
        kthread+0x110/0x114
        ret_from_fork+0x10/0x20

-&gt; #0 (component_mutex){+.+.}-{3:3}:
        __lock_acquire+0x1280/0x20ac
        lock_acquire.part.0+0xe0/0x230
        lock_acquire+0x6c/0x90
        __mutex_lock+0x84/0x400
        mutex_lock_nested+0x3c/0x70
        component_del+0x34/0x170
        dsi_dev_detach+0x24/0x30
        dsi_host_detach+0x20/0x64
        mipi_dsi_detach+0x2c/0x40
        adv7533_mode_set+0x64/0x90
        adv7511_bridge_mode_set+0x210/0x214
        drm_bridge_chain_mode_set+0x5c/0x84
        crtc_set_mode+0x18c/0x1dc
        drm_atomic_helper_commit_modeset_disables+0x40/0x50
        msm_atomic_commit_tail+0x1d0/0x6e0
        commit_tail+0xa4/0x180
        drm_atomic_helper_commit+0x178/0x3b0
        drm_atomic_commit+0xa4/0xe0
        drm_client_modeset_commit_atomic+0x228/0x284
        drm_client_modeset_commit_locked+0x64/0x1d0
        drm_client_modeset_commit+0x34/0x60
        drm_fb_helper_lastclose+0x74/0xcc
        drm_lastclose+0x3c/0x80
        drm_release+0xfc/0x114
        __fput+0x70/0x224
        ____fput+0x14/0x20
        task_work_run+0x88/0x1a0
        do_exit+0x350/0xa50
        do_group_exit+0x38/0xa4
        __wake_up_parent+0x0/0x34
        invoke_syscall+0x48/0x114
        el0_svc_common.constprop.0+0x60/0x11c
        do_el0_svc+0x30/0xc0
        el0_svc+0x58/0x100
        el0t_64_sync_handler+0x1b0/0x1bc
        el0t_64_sync+0x18c/0x190

Due to above reasons, remove the dynamic lane switching
code from adv7533 bridge chip and filter out the modes
which would need different number of lanes as compared
to the initialization time using the mode_valid callback.

This can be potentially re-introduced by using the pre_enable()
callback but this needs to be evaluated first whether such an
approach will work so this will be done with a separate change.

changes since RFC:
	- Fix commit text and add TODO comment

changes in v2:
	- Fix checkpatch formatting errors

Fixes: 62b2f026cd8e ("drm/bridge: adv7533: Change number of DSI lanes dynamically")
Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/16
Suggested-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Reviewed-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://lore.kernel.org/r/1661797363-7564-1-git-send-email-quic_abhinavk@quicinc.com
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1665522649-3423-1-git-send-email-quic_abhinavk@quicinc.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm: bridge: dw_hdmi: fix preference of RGB modes over YUV420</title>
<updated>2022-12-14T10:40:58+00:00</updated>
<author>
<name>Guillaume BRUN</name>
<email>the.cheaterman@gmail.com</email>
</author>
<published>2022-11-16T14:35:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=52f5219f4853b57d5cdabffb03210cf709698263'/>
<id>urn:sha1:52f5219f4853b57d5cdabffb03210cf709698263</id>
<content type='text'>
[ Upstream commit d3d6b1bf85aefe0ebc0624574b3bb62f0693914c ]

Cheap monitors sometimes advertise YUV modes they don't really have
(HDMI specification mandates YUV support so even monitors without actual
support will often wrongfully advertise it) which results in YUV matches
and user forum complaints of a red tint to light colour display areas in
common desktop environments.

Moving the default RGB fall-back before YUV selection results in RGB
mode matching in most cases, reducing complaints.

Fixes: 6c3c719936da ("drm/bridge: synopsys: dw-hdmi: add bus format negociation")
Signed-off-by: Guillaume BRUN &lt;the.cheaterman@gmail.com&gt;
Tested-by: Christian Hewitt &lt;christianshewitt@gmail.com&gt;
Reviewed-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Signed-off-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20221116143523.2126-1-the.cheaterman@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/bridge: ti-sn65dsi86: Fix output polarity setting bug</title>
<updated>2022-12-14T10:40:57+00:00</updated>
<author>
<name>Qiqi Zhang</name>
<email>eddy.zhang@rock-chips.com</email>
</author>
<published>2022-11-25T10:45:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=693d8e313868cf84a9b3c87c4ccffe81bb3e2180'/>
<id>urn:sha1:693d8e313868cf84a9b3c87c4ccffe81bb3e2180</id>
<content type='text'>
[ Upstream commit 8c115864501fc09932cdfec53d9ec1cde82b4a28 ]

According to the description in ti-sn65dsi86's datasheet:

CHA_HSYNC_POLARITY:
0 = Active High Pulse. Synchronization signal is high for the sync
pulse width. (default)
1 = Active Low Pulse. Synchronization signal is low for the sync
pulse width.

CHA_VSYNC_POLARITY:
0 = Active High Pulse. Synchronization signal is high for the sync
pulse width. (Default)
1 = Active Low Pulse. Synchronization signal is low for the sync
pulse width.

We should only set these bits when the polarity is negative.

Fixes: a095f15c00e2 ("drm/bridge: add support for sn65dsi86 bridge driver")
Signed-off-by: Qiqi Zhang &lt;eddy.zhang@rock-chips.com&gt;
Reviewed-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Tested-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20221125104558.84616-1-eddy.zhang@rock-chips.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/bridge: ps8640: Add back the 50 ms mystery delay after HPD</title>
<updated>2022-11-03T15:00:30+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2022-10-17T19:18:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0c2a107b26c8e1ee3dccf31b27d7752f3041028f'/>
<id>urn:sha1:0c2a107b26c8e1ee3dccf31b27d7752f3041028f</id>
<content type='text'>
[ Upstream commit cb8e30ddb7e345867f6f2da8a08291d7d9e037db ]

Back in commit 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable
runtime power management") we removed a mysterious 50 ms delay because
"Parade's support [couldn't] explain what the delay [was] for".

While I'm always a fan of removing mysterious delays, I suspect that
we need this mysterious delay to avoid some problems.

Specifically, what I found recently is that on sc7180-trogdor-homestar
sometimes the AUX backlight wasn't initializing properly. Some
debugging showed that the drm_dp_dpcd_read() function that the AUX
backlight driver was calling was returning bogus data about 1% of the
time when I booted up. This confused
drm_panel_dp_aux_backlight(). From continued debugging:
- If I retried the read then the read worked just fine.
- If I added a loop to perform the same read that
  drm_panel_dp_aux_backlight() was doing 30 times at bootup I could
  see that some percentage of the time the first read would give bogus
  data but all 29 additional reads would always be fine.
- If I added a large delay _after_ powering on the panel but before
  powering on PS8640 I could still reproduce the problem.
- If I added a delay after PS8640 powered on then I couldn't reproduce
  the problem.
- I couldn't reproduce the problem on a board with the same panel but
  the ti-sn65dsi86 bridge chip.

To me, the above indicated that there was a problem with PS8640 and
not the panel.

I don't really have any insight into what's going on in the MCU, but
my best guess is that when the MCU itself sees the HPD go high that it
does some AUX transfers itself and this is confusing things.

Let's go back and add back in the mysterious 50 ms delay. We only want
to do this the first time we see HPD go high after booting the MCU,
not every time we double-check HPD.

With this, the backlight initializes reliably on homestar.

Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
Reviewed-by: Stephen Boyd &lt;swboyd@chromium.org&gt;
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20221017121813.1.I59700c745fbc31559a5d5c8e2a960279c751dbd5@changeid
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm: bridge: dw_hdmi: only trigger hotplug event on link change</title>
<updated>2022-10-21T10:39:13+00:00</updated>
<author>
<name>Lucas Stach</name>
<email>l.stach@pengutronix.de</email>
</author>
<published>2022-08-26T18:57:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6d04eff23f4b3fe411b3844459d9f33f545de8cb'/>
<id>urn:sha1:6d04eff23f4b3fe411b3844459d9f33f545de8cb</id>
<content type='text'>
[ Upstream commit da09daf881082266e4075657fac53c7966de8e4d ]

There are two events that signal a real change of the link state: HPD going
high means the sink is newly connected or wants the source to re-read the
EDID, RX sense going low is a indication that the link has been disconnected.

Ignore the other two events that also trigger interrupts, but don't need
immediate attention: HPD going low does not necessarily mean the link has
been lost and should not trigger a immediate read of the status. RX sense
going high also does not require a detect cycle, as HPD going high is the
right point in time to read the EDID.

Signed-off-by: Lucas Stach &lt;l.stach@pengutronix.de&gt;
Reviewed-by: Neil Armstrong &lt;narmstrong@baylibre.com&gt; (v1)
Reviewed-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220826185733.3213248-1-l.stach@pengutronix.de
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpu: lontium-lt9611: Fix NULL pointer dereference in lt9611_connector_init()</title>
<updated>2022-10-21T10:39:12+00:00</updated>
<author>
<name>Zeng Jingxiang</name>
<email>linuszeng@tencent.com</email>
</author>
<published>2022-07-27T07:31:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=912f84e15e94ab87f5a7156aa1870090373d8304'/>
<id>urn:sha1:912f84e15e94ab87f5a7156aa1870090373d8304</id>
<content type='text'>
[ Upstream commit ef8886f321c5dab8124b9153d25afa2a71d05323 ]

A NULL check for bridge-&gt;encoder shows that it may be NULL, but it
already been dereferenced on all paths leading to the check.
812	if (!bridge-&gt;encoder) {

Dereference the pointer bridge-&gt;encoder.
810	drm_connector_attach_encoder(&amp;lt9611-&gt;connector, bridge-&gt;encoder);

Signed-off-by: Zeng Jingxiang &lt;linuszeng@tencent.com&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220727073119.1578972-1-zengjx95@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/bridge: it6505: Fix the order of DP_SET_POWER commands</title>
<updated>2022-10-21T10:38:26+00:00</updated>
<author>
<name>Pin-yen Lin</name>
<email>treapking@chromium.org</email>
</author>
<published>2022-08-30T04:57:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c62af469e5d18b184c1e653a9a8a960fc5241a99'/>
<id>urn:sha1:c62af469e5d18b184c1e653a9a8a960fc5241a99</id>
<content type='text'>
[ Upstream commit 7c1dceaffd99247bf443606730515b54d6285969 ]

Send DP_SET_POWER_D3 command to the downstream before stopping DP, so the
suspend process will not be interrupted by the HPD interrupt. Also modify
the order in .atomic_enable callback to make the callbacks symmetric.

Fixes: 46ca7da7f1e8 ("drm/bridge: it6505: Send DPCD SET_POWER to downstream")
Signed-off-by: Pin-yen Lin &lt;treapking@chromium.org&gt;
Reviewed-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220830045756.1655954-1-treapking@chromium.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/bridge: megachips: Fix a null pointer dereference bug</title>
<updated>2022-10-21T10:38:25+00:00</updated>
<author>
<name>Zheyu Ma</name>
<email>zheyuma97@gmail.com</email>
</author>
<published>2022-08-30T07:34:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7371fad5cfe6eada6bb5523c895fd6074b15c2b9'/>
<id>urn:sha1:7371fad5cfe6eada6bb5523c895fd6074b15c2b9</id>
<content type='text'>
[ Upstream commit 1ff673333d46d2c1b053ebd0c1c7c7c79e36943e ]

When removing the module we will get the following warning:

[   31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
[   31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
[   31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[   31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
[   31.921825] Call Trace:
[   31.922533]  stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw]
[   31.923139]  i2c_device_remove+0x181/0x1f0

The two bridges (stdp2690, stdp4028) do not probe at the same time, so
the driver does not call ge_b850v3_resgiter() when probing, causing the
driver to try to remove the object that has not been initialized.

Fix this by checking whether both the bridges are probed.

Fixes: 11632d4aa2b3 ("drm/bridge: megachips: Ensure both bridges are probed before registration")
Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220830073450.1897020-1-zheyuma97@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/bridge: parade-ps8640: Fix regulator supply order</title>
<updated>2022-10-21T10:38:22+00:00</updated>
<author>
<name>Chen-Yu Tsai</name>
<email>wenst@chromium.org</email>
</author>
<published>2022-07-21T09:22:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6004d6ca974280abff9f6bc6c4f1353679350b06'/>
<id>urn:sha1:6004d6ca974280abff9f6bc6c4f1353679350b06</id>
<content type='text'>
[ Upstream commit fc94224c2e0ae8d83ac511a3ef4962178505469d ]

The datasheet says that VDD12 must be enabled and at full voltage before
VDD33 is enabled.

Reorder the bulk regulator supply names so that VDD12 is enabled before
VDD33. Any enable ramp delays should be handled by setting proper
constraints on the regulators.

Fixes: bc1aee7fc8f0 ("drm/bridge: Add I2C based driver for ps8640 bridge")
Signed-off-by: Chen-Yu Tsai &lt;wenst@chromium.org&gt;
Reviewed-by: Neil Armstrong &lt;narmstrong@baylibre.com&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220721092258.3397461-1-wenst@chromium.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
