<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/gpu/drm/msm/dsi, branch v6.6.134</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.134</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.134'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-03-25T10:05:45+00:00</updated>
<entry>
<title>drm/msm/dsi: fix pclk rate calculation for bonded dsi</title>
<updated>2026-03-25T10:05:45+00:00</updated>
<author>
<name>Pengyu Luo</name>
<email>mitltlatltl@gmail.com</email>
</author>
<published>2026-03-06T16:32:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=43723dff1a59d6aa25dd6b81129ff747be2e52c5'/>
<id>urn:sha1:43723dff1a59d6aa25dd6b81129ff747be2e52c5</id>
<content type='text'>
[ Upstream commit e4eb11b34d6c84f398d8f08d7cb4d6c38e739dd2 ]

Recently, we round up new_hdisplay once at most, for bonded dsi, we
may need twice, since they are independent links, we should round up
each half separately. This also aligns with the hdisplay we program
later in dsi_timing_setup()

Example:
	full_hdisplay = 1904, dsc_bpp = 8, bpc = 8
	new_full_hdisplay = DIV_ROUND_UP(1904 * 8, 8 * 3) = 635

if we use half display
	new_half_hdisplay = DIV_ROUND_UP(952 * 8, 8 * 3) = 318
	new_full_display = 636

Fixes: 7c9e4a554d4a ("drm/msm/dsi: Reduce pclk rate for compression")
Signed-off-by: Pengyu Luo &lt;mitltlatltl@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Patchwork: https://patchwork.freedesktop.org/patch/709716/
Link: https://lore.kernel.org/r/20260306163255.215456-1-mitltlatltl@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi: Document DSC related pclk_rate and hdisplay calculations</title>
<updated>2026-03-25T10:05:45+00:00</updated>
<author>
<name>Dmitry Baryshkov</name>
<email>dmitry.baryshkov@linaro.org</email>
</author>
<published>2024-02-08T15:23:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7c370f2cb7fc8b66d0cab08feb03555d46e1b02e'/>
<id>urn:sha1:7c370f2cb7fc8b66d0cab08feb03555d46e1b02e</id>
<content type='text'>
[ Upstream commit 3b56d27ba1578c3d61f51de4102cf896a9a8617e ]

Provide actual documentation for the pclk and hdisplay calculations in
the case of DSC compression being used.

Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Patchwork: https://patchwork.freedesktop.org/patch/577534/
Link: https://lore.kernel.org/r/20240208-fd_document_dsc_pclk_rate-v4-1-56fe59d0a2e0@linaro.org
Stable-dep-of: e4eb11b34d6c ("drm/msm/dsi: fix pclk rate calculation for bonded dsi")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi/phy_7nm: Fix missing initial VCO rate</title>
<updated>2025-11-24T09:29:32+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@linaro.org</email>
</author>
<published>2025-06-10T14:05:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0d629175a7ee2888834515b5954177ce3aa58f24'/>
<id>urn:sha1:0d629175a7ee2888834515b5954177ce3aa58f24</id>
<content type='text'>
[ Upstream commit 5ddcb0cb9d10e6e70a68e0cb8f0b8e3a7eb8ccaf ]

Driver unconditionally saves current state on first init in
dsi_pll_7nm_init(), but does not save the VCO rate, only some of the
divider registers.  The state is then restored during probe/enable via
msm_dsi_phy_enable() -&gt; msm_dsi_phy_pll_restore_state() -&gt;
dsi_7nm_pll_restore_state().

Restoring calls dsi_pll_7nm_vco_set_rate() with
pll_7nm-&gt;vco_current_rate=0, which basically overwrites existing rate of
VCO and messes with clock hierarchy, by setting frequency to 0 to clock
tree.  This makes anyway little sense - VCO rate was not saved, so
should not be restored.

If PLL was not configured configure it to minimum rate to avoid glitches
and configuring entire in clock hierarchy to 0 Hz.

Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Patchwork: https://patchwork.freedesktop.org/patch/657827/
Link: https://lore.kernel.org/r/20250610-b4-sm8750-display-v6-9-ee633e3ddbff@linaro.org
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi/phy: Toggle back buffer resync after preparing PLL</title>
<updated>2025-11-24T09:29:32+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@linaro.org</email>
</author>
<published>2025-06-10T14:05:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b093c81df23f514a6853baaa4ad384979e620deb'/>
<id>urn:sha1:b093c81df23f514a6853baaa4ad384979e620deb</id>
<content type='text'>
[ Upstream commit b63f008f395ca5f6bc89123db97440bdc19981c4 ]

According to Hardware Programming Guide for DSI PHY, the retime buffer
resync should be done after PLL clock users (byte_clk and intf_byte_clk)
are enabled.  Downstream also does it as part of configuring the PLL.

Driver was only turning off the resync FIFO buffer, but never bringing it
on again.

Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Patchwork: https://patchwork.freedesktop.org/patch/657823/
Link: https://lore.kernel.org/r/20250610-b4-sm8750-display-v6-6-ee633e3ddbff@linaro.org
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi/dsi_phy_10nm: Fix missing initial VCO rate</title>
<updated>2025-06-27T10:09:01+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@linaro.org</email>
</author>
<published>2025-05-20T11:13:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=002aa3ed19f3407622c2906d7f9eb2d5172cf648'/>
<id>urn:sha1:002aa3ed19f3407622c2906d7f9eb2d5172cf648</id>
<content type='text'>
[ Upstream commit 8a48e35becb214743214f5504e726c3ec131cd6d ]

Driver unconditionally saves current state on first init in
dsi_pll_10nm_init(), but does not save the VCO rate, only some of the
divider registers.  The state is then restored during probe/enable via
msm_dsi_phy_enable() -&gt; msm_dsi_phy_pll_restore_state() -&gt;
dsi_10nm_pll_restore_state().

Restoring calls dsi_pll_10nm_vco_set_rate() with
pll_10nm-&gt;vco_current_rate=0, which basically overwrites existing rate of
VCO and messes with clock hierarchy, by setting frequency to 0 to clock
tree.  This makes anyway little sense - VCO rate was not saved, so
should not be restored.

If PLL was not configured configure it to minimum rate to avoid glitches
and configuring entire in clock hierarchy to 0 Hz.

Suggested-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Link: https://lore.kernel.org/r/sz4kbwy5nwsebgf64ia7uq4ee7wbsa5uy3xmlqwcstsbntzcov@ew3dcyjdzmi2/
Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Fixes: a4ccc37693a2 ("drm/msm/dsi_pll_10nm: restore VCO rate during
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Patchwork: https://patchwork.freedesktop.org/patch/654796/
Link: https://lore.kernel.org/r/20250520111325.92352-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi: Set PHY usescase (and mode) before registering DSI host</title>
<updated>2025-04-10T12:37:28+00:00</updated>
<author>
<name>Marijn Suijten</name>
<email>marijn.suijten@somainline.org</email>
</author>
<published>2025-02-17T11:17:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a984e6108c9cbfbcc470c259cdfb1ed3708fd632'/>
<id>urn:sha1:a984e6108c9cbfbcc470c259cdfb1ed3708fd632</id>
<content type='text'>
[ Upstream commit 660c396c98c061f9696bebacc178b74072e80054 ]

Ordering issues here cause an uninitialized (default STANDALONE)
usecase to be programmed (which appears to be a MUX) in some cases
when msm_dsi_host_register() is called, leading to the slave PLL in
bonded-DSI mode to source from a clock parent (dsi1vco) that is off.

This should seemingly not be a problem as the actual dispcc clocks from
DSI1 that are muxed in the clock tree of DSI0 are way further down, this
bit still seems to have an effect on them somehow and causes the right
side of the panel controlled by DSI1 to not function.

In an ideal world this code is refactored to no longer have such
error-prone calls "across subsystems", and instead model the "PLL src"
register field as a regular mux so that changing the clock parents
programmatically or in DTS via `assigned-clock-parents` has the
desired effect.
But for the avid reader, the clocks that we *are* muxing into DSI0's
tree are way further down, so if this bit turns out to be a simple mux
between dsiXvco and out_div, that shouldn't have any effect as this
whole tree is off anyway.

Fixes: 57bf43389337 ("drm/msm/dsi: Pass down use case to PHY")
Reviewed-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Marijn Suijten &lt;marijn.suijten@somainline.org&gt;
Patchwork: https://patchwork.freedesktop.org/patch/637650/
Link: https://lore.kernel.org/r/20250217-drm-msm-initial-dualpipe-dsc-fixes-v3-2-913100d6103f@somainline.org
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi: Use existing per-interface slice count in DSC timing</title>
<updated>2025-04-10T12:37:28+00:00</updated>
<author>
<name>Marijn Suijten</name>
<email>marijn.suijten@somainline.org</email>
</author>
<published>2025-02-17T11:17:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7570e56930921f0bff3667f557ca21ecab75ff9b'/>
<id>urn:sha1:7570e56930921f0bff3667f557ca21ecab75ff9b</id>
<content type='text'>
[ Upstream commit 14ad809ceb66d0874cbe4bd5ca9edf0de8d9ad96 ]

When configuring the timing of DSI hosts (interfaces) in
dsi_timing_setup() all values written to registers are taking
bonded-mode into account by dividing the original mode width by 2
(half the data is sent over each of the two DSI hosts), but the full
width instead of the interface width is passed as hdisplay parameter to
dsi_update_dsc_timing().

Currently only msm_dsc_get_slices_per_intf() is called within
dsi_update_dsc_timing() with the `hdisplay` argument which clearly
documents that it wants the width of a single interface (which, again,
in bonded DSI mode is half the total width of the mode) resulting in all
subsequent values to be completely off.

However, as soon as we start to pass the halved hdisplay
into dsi_update_dsc_timing() we might as well discard
msm_dsc_get_slices_per_intf() since the value it calculates is already
available in dsc-&gt;slice_count which is per-interface by the current
design of MSM DPU/DSI implementations and their use of the DRM DSC
helpers.

Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Jessica Zhang &lt;quic_jesszhan@quicinc.com&gt;
Signed-off-by: Marijn Suijten &lt;marijn.suijten@somainline.org&gt;
Patchwork: https://patchwork.freedesktop.org/patch/637648/
Link: https://lore.kernel.org/r/20250217-drm-msm-initial-dualpipe-dsc-fixes-v3-1-913100d6103f@somainline.org
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi: fix 32-bit signed integer extension in pclk_rate calculation</title>
<updated>2024-11-01T00:58:21+00:00</updated>
<author>
<name>Jonathan Marek</name>
<email>jonathan@marek.ca</email>
</author>
<published>2024-10-07T05:01:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=33ece6c4f0c1e1133f54cc53b73fbc27965a585e'/>
<id>urn:sha1:33ece6c4f0c1e1133f54cc53b73fbc27965a585e</id>
<content type='text'>
[ Upstream commit 358b762400bd94db2a14a72dfcef74c7da6bd845 ]

When (mode-&gt;clock * 1000) is larger than (1&lt;&lt;31), int to unsigned long
conversion will sign extend the int to 64 bits and the pclk_rate value
will be incorrect.

Fix this by making the result of the multiplication unsigned.

Note that above (1&lt;&lt;32) would still be broken and require more changes, but
its unlikely anyone will need that anytime soon.

Fixes: c4d8cfe516dc ("drm/msm/dsi: add implementation for helper functions")
Signed-off-by: Jonathan Marek &lt;jonathan@marek.ca&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Patchwork: https://patchwork.freedesktop.org/patch/618434/
Link: https://lore.kernel.org/r/20241007050157.26855-2-jonathan@marek.ca
Signed-off-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi: improve/fix dsc pclk calculation</title>
<updated>2024-11-01T00:58:21+00:00</updated>
<author>
<name>Jonathan Marek</name>
<email>jonathan@marek.ca</email>
</author>
<published>2024-10-07T05:01:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9f2361089152467f4819828f7826f1a9aebe1e9a'/>
<id>urn:sha1:9f2361089152467f4819828f7826f1a9aebe1e9a</id>
<content type='text'>
[ Upstream commit 24436a540d16ca6a523b8e5441180001c31b6b35 ]

drm_mode_vrefresh() can introduce a large rounding error, avoid it.

Fixes: 7c9e4a554d4a ("drm/msm/dsi: Reduce pclk rate for compression")
Signed-off-by: Jonathan Marek &lt;jonathan@marek.ca&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Patchwork: https://patchwork.freedesktop.org/patch/618432/
Link: https://lore.kernel.org/r/20241007050157.26855-1-jonathan@marek.ca
Signed-off-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drm/msm/dsi: correct programming sequence for SM8350 / SM8450</title>
<updated>2024-10-04T14:29:12+00:00</updated>
<author>
<name>Dmitry Baryshkov</name>
<email>dmitry.baryshkov@linaro.org</email>
</author>
<published>2024-08-04T05:40:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=476945372b1f8b78fb30c5b191ef4c24a210dcad'/>
<id>urn:sha1:476945372b1f8b78fb30c5b191ef4c24a210dcad</id>
<content type='text'>
[ Upstream commit 1328cb7c34bf6d056df9ff694ee5194537548258 ]

According to the display-drivers, 5nm DSI PLL (v4.2, v4.3) have
different boundaries for pll_clock_inverters programming. Follow the
vendor code and use correct values.

Fixes: 2f9ae4e395ed ("drm/msm/dsi: add support for DSI-PHY on SM8350 and SM8450")
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Patchwork: https://patchwork.freedesktop.org/patch/606947/
Link: https://lore.kernel.org/r/20240804-sm8350-fixes-v1-3-1149dd8399fe@linaro.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
