linux-stable.git/drivers/gpu/drm/msm/dp/dp_ctrl.c, branch linux-6.8.y

drm/msm/dp: allow voltage swing / pre emphasis of 3

2024-05-30T07:49:38+00:00

[ Upstream commit 22578178e5dd6d3aa4490879df8b6c2977d980be ]

Both dp_link_adjust_levels() and dp_ctrl_update_vx_px() limit swing and
pre-emphasis to 2, while the real maximum value for the sum of the
voltage swing and pre-emphasis is 3. Fix the DP code to remove this
limitation.

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Dmitry Baryshkov 
Reviewed-by: Kuogee Hsieh 
Tested-by: Kuogee Hsieh 
Patchwork: https://patchwork.freedesktop.org/patch/577006/
Link: https://lore.kernel.org/r/20240203-dp-swing-3-v1-1-6545e1706196@linaro.org
Signed-off-by: Sasha Levin

drm/msms/dp: fixed link clock divider bits be over written in BPC unknown case

2024-01-24T22:06:24+00:00

Since the value of DP_TEST_BIT_DEPTH_8 is already left shifted, in the
BPC unknown case, the additional shift causes spill over to the other
bits of the [DP_CONFIGURATION_CTRL] register.
Fix this by changing the return value of dp_link_get_test_bits_depth()
in the BPC unknown case to (DP_TEST_BIT_DEPTH_8 >> DP_TEST_BIT_DEPTH_SHIFT).

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Kuogee Hsieh 
Reviewed-by: Abhinav Kumar 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/573989/
Link: https://lore.kernel.org/r/1704917931-30133-1-git-send-email-quic_khsieh@quicinc.com
[quic_abhinavk@quicinc.com: fix minor checkpatch warning to align with opening braces]
Signed-off-by: Abhinav Kumar

drm/msm/dp: do not reinitialize phy unless retry during link training

2023-09-20T23:19:24+00:00

DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
cause PLL unlocked initially and then PLL gets locked at the end of
initialization. PLL_UNLOCKED interrupt will fire during this time if the
interrupt mask is enabled.

However currently DP driver link training implementation incorrectly
re-initializes PHY unconditionally during link training as the PHY was
already configured in dp_ctrl_enable_mainlink_clocks().

Fix this by re-initializing the PHY only if the previous link training
failed.

[drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
Signed-off-by: Kuogee Hsieh 
Tested-by: Abhinav Kumar  # sc7280
Reviewed-by: Abhinav Kumar 
Reviewed-by: Stephen Boyd 
Reviewed-by: Dmitry Baryshkov 
Tested-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/551847/
Link: https://lore.kernel.org/r/1691533190-19335-1-git-send-email-quic_khsieh@quicinc.com
[quic_abhinavk@quicinc.com: added line break in commit text]
Signed-off-by: Abhinav Kumar

drm/msm/dp: Return IRQ_NONE for unhandled interrupts

2023-04-06T17:29:44+00:00

If our interrupt handler gets called and we don't really handle the
interrupt then we should return IRQ_NONE. The current interrupt
handler didn't do this, so let's fix it.

NOTE: for some of the cases it's clear that we should return IRQ_NONE
and some cases it's clear that we should return IRQ_HANDLED. However,
there are a few that fall somewhere in between. Specifically, the
documentation for when to return IRQ_NONE vs. IRQ_HANDLED is probably
best spelled out in the commit message of commit d9e4ad5badf4 ("Document
that IRQ_NONE should be returned when IRQ not actually handled"). That
commit makes it clear that we should return IRQ_HANDLED if we've done
something to make the interrupt stop happening.

The case where it's unclear is, for instance, in dp_aux_isr() after
we've read the interrupt using dp_catalog_aux_get_irq() and confirmed
that "isr" is non-zero. The function dp_catalog_aux_get_irq() not only
reads the interrupts but it also "ack"s all the interrupts that are
returned. For an "unknown" interrupt this has a very good chance of
actually stopping the interrupt from happening. That would mean we've
identified that it's our device and done something to stop them from
happening and should return IRQ_HANDLED. Specifically, it should be
noted that most interrupts that need "ack"ing are ones that are
one-time events and doing an "ack" is enough to clear them. However,
since these interrupts are unknown then, by definition, it's unknown
if "ack"ing them is truly enough to clear them. It's possible that we
also need to remove the original source of the interrupt. In this
case, IRQ_NONE would be a better choice.

Given that returning an occasional IRQ_NONE isn't the absolute end of
the world, however, let's choose that course of action. The IRQ
framework will forgive a few IRQ_NONE returns now and again (and it
won't even log them, which is why we have to log them ourselves). This
means that if we _do_ end hitting an interrupt where "ack"ing isn't
enough the kernel will eventually detect the problem and shut our
device down.

Signed-off-by: Douglas Anderson 
Tested-by: Kuogee Hsieh 
Reviewed-by: Kuogee Hsieh 
Patchwork: https://patchwork.freedesktop.org/patch/520660/
Link: https://lore.kernel.org/r/20230126170745.v2.2.I2d7aec2fadb9c237cd0090a47d6a8ba2054bf0f8@changeid
[DB: reformatted commit message to make checkpatch happy]
Signed-off-by: Dmitry Baryshkov

drm/msm/dp: Add basic PSR support for eDP

2023-03-13T01:43:49+00:00

Add support for basic panel self refresh (PSR) feature for eDP.
Add a new interface to set PSR state in the sink from DPU.
Program the eDP controller to issue PSR enter and exit SDP to
the sink.

Signed-off-by: Sankeerth Billakanti 
Signed-off-by: Vinod Polimera 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/524734/
Link: https://lore.kernel.org/r/1677774797-31063-10-git-send-email-quic_vpolimer@quicinc.com
Signed-off-by: Dmitry Baryshkov

drm/msm/dp: cleared DP_DOWNSPREAD_CTRL register before start link training

2022-09-30T16:57:53+00:00

DOWNSPREAD_CTRL (0x107) shall be cleared to 0 upon power-on reset or an
upstream device disconnect. This patch will enforce this rule by always
cleared DOWNSPREAD_CTRL register to 0 before start link training. At rare
case that DP MSA timing parameters may be mis-interpreted by the sink
which causes audio sampling rate be calculated wrongly and cause audio
did not work at sink if DOWNSPREAD_CTRL register is not cleared to 0.

Changes in v2:
1) fix spelling at commit text
2) merge ssc variable into encoding[0]

Changes in v3:
-- correct spelling of DOWNSPREAD_CTRL
-- replace err with len of ssize_t

Changes in v4:
-- split into 2 patches

Signed-off-by: Kuogee Hsieh 
Reviewed-by: Dmitry Baryshkov 
Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Patchwork: https://patchwork.freedesktop.org/patch/502532/
Link: https://lore.kernel.org/r/1662999830-13916-2-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Abhinav Kumar

drm/msm/dp: Get rid of dp_ctrl_on_stream_phy_test_report()

2022-09-18T16:38:04+00:00

This API isn't really more than a couple lines now that we don't store
the pixel_rate to the struct member. Inline it into the caller.

Cc: Kuogee Hsieh 
Signed-off-by: Stephen Boyd 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/490775/
Link: https://lore.kernel.org/r/20220623002540.871994-4-swboyd@chromium.org
Signed-off-by: Dmitry Baryshkov 
Signed-off-by: Rob Clark

drm/msm/dp: Remove pixel_rate from struct dp_ctrl

2022-09-18T16:38:04+00:00

This struct member is stored to in the function that calls the function
which uses it. That's possible with a function argument instead of
storing to a struct member. Pass the pixel_rate as an argument instead
to simplify the code. Note that dp_ctrl_link_maintenance() was storing
the pixel_rate but never using it so we just remove the assignment from
there.

Cc: Kuogee Hsieh 
Signed-off-by: Stephen Boyd 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/490772/
Link: https://lore.kernel.org/r/20220623002540.871994-3-swboyd@chromium.org
Signed-off-by: Dmitry Baryshkov 
Signed-off-by: Rob Clark

drm/msm/dp: Reorganize code to avoid forward declaration

2022-09-18T16:38:04+00:00

Let's move these functions around to avoid having to forward declare
dp_ctrl_on_stream_phy_test_report(). Also remove
dp_ctrl_reinitialize_mainlink() forward declaration because we're doing
that sort of task.

Reviewed-by: Kuogee Hsieh 
Reviewed-by: Dmitry Baryshkov 
Signed-off-by: Stephen Boyd 
Patchwork: https://patchwork.freedesktop.org/patch/490771/
Link: https://lore.kernel.org/r/20220623002540.871994-2-swboyd@chromium.org
Signed-off-by: Dmitry Baryshkov 
Signed-off-by: Rob Clark

drm/msm/dp: delete DP_RECOVERED_CLOCK_OUT_EN to fix tps4

2022-09-18T16:37:55+00:00

Data Symbols scrambled is required for tps4 at link training 2.
Therefore SCRAMBLING_DISABLE bit should not be set for tps4 to
work.

RECOVERED_CLOCK_OUT_EN is for enable simple EYE test for jitter
measurement with minimal equipment for embedded applications purpose
and is not required to be set during normal operation. Current
implementation always have RECOVERED_CLOCK_OUT_EN bit set which
cause SCRAMBLING_DISABLE bit wrongly set at tps4 which prevent
tps4 from working.

This patch delete setting RECOVERED_CLOCK_OUT_EN to fix
SCRAMBLING_DISABLE be wrongly set at tps4.

Changes in v2:
-- fix Fixes tag

Changes in v3:
-- revise commit text

Changes in v4:
-- fix commit text newline

Changes in v5:
-- fix commit text line over 75 chars

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Kuogee Hsieh 

Reviewed-by: Abhinav Kumar 
Reviewed-by: Stephen Boyd 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/497194/
Link: https://lore.kernel.org/r/1660258670-4200-1-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Abhinav Kumar 
Signed-off-by: Rob Clark