[ Upstream commit 7b4d8db657192066bc6f1f6635d348413dac1e18 ]
The sequence for Source DP PHY CTS automation is [2][1]:
1- Emulate successful Link Training(LT)
2- Short HPD and change link rates and number of lanes by LT.
(This is same flow for Link Layer CTS)
3- Short HPD and change PHY test pattern and swing/pre-emphasis
levels (This step should not trigger LT)
The problem is with DP PHY compliance setup as follow:
[DPTX + on board LTTPR]------Main Link--->[Scope]
^ |
| |
| |
----------Aux Ch------>[Aux Emulator]
At step 3, before writing TRAINING_LANEx_SET/LINK_QUAL_PATTERN_SET
to declare the pattern/swing requested by scope, we write link
config in LINK_BW_SET/LANE_COUNT_SET on a port that has LTTPR.
As LTTPR snoops aux transaction, LINK_BW_SET/LANE_COUNT_SET writes
indicate a LT will start [Check DP 2.0 E11 -Sec 3.6.8.2 & 3.6.8.6.3],
and LTTPR will reset the link and stop sending DP signals to
DPTX/Scope causing the measurements to fail. Note that step 3 will
not trigger LT and DP link will never recovered by the
Aux Emulator/Scope.
The reset of link can be tested with a monitor connected to LTTPR
port simply by writing to LINK_BW_SET or LANE_COUNT_SET as follow
igt/tools/dpcd_reg write --offset=0x100 --value 0x14 --device=2
OR
printf '\x14' | sudo dd of=/dev/drm_dp_aux2 bs=1 count=1 conv=notrunc
seek=$((0x100))
This single aux write causes the screen to blank, sending short HPD to
DPTX, setting LINK_STATUS_UPDATE = 1 in DPCD 0x204, and triggering LT.
As stated in [1]:
"Before any TX electrical testing can be performed, the link between a
DPTX and DPRX (in this case, a piece of test equipment), including all
LTTPRs within the path, shall be trained as defined in this Standard."
In addition, changing Phy pattern/Swing/Pre-emphasis (Step 3) uses the
same link rate and lane count applied on step 2, so no need to redo LT.
The fix is to not rewrite link config in step 3, and just writes
TRAINING_LANEx_SET and LINK_QUAL_PATTERN_SET
[1]: DP 2.0 E11 - 3.6.11.1 LTTPR DPTX_PHY Electrical Compliance
[2]: Configuring UnigrafDPTC Controller - Automation Test Sequence
https://www.keysight.com/us/en/assets/9922-01244/help-files/
D9040DPPC-DisplayPort-Test-Software-Online-Help-latest.chm
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Or Cochvi <or.cochvi@intel.com>
Signed-off-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220916054900.415804-1-khaled.almahallawy@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2ac6cdd581f48c8f68747156fde5868486a44985 ]
drm_dp_dpcd_read returns the number of bytes read. The previous code
would print garbage on DPCD error, and would exit with on error on
success.
Signed-off-by: Simon Ser <contact@emersion.fr>
Fixes: cb897542c6d2 ("drm/dp_mst: Fix W=1 warnings")
Cc: Lyude Paul <lyude@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/473500/
Signed-off-by: Sasha Levin <sashal@kernel.org>
drm_crtc.h has no need for linux/fb.h, so don't include it. Avoids useless rebuilds of the entire universe when touching linux/fb.h. Quite a few placs do currently depend on linux/fb.h or other headers pulled in by it without actually including any of it directly. All of those need to be fixed up. v2: Split the vmwgfx change out Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220630195114.17407-3-ville.syrjala@linux.intel.com
While CONFIG_OF is n but COMPILE_TEST is y, we got this:
WARNING: unmet direct dependencies detected for DRM_DP_AUX_BUS
Depends on [n]: HAS_IOMEM [=y] && DRM [=y] && OF [=n]
Selected by [y]:
- DRM_MSM [=y] && HAS_IOMEM [=y] && DRM [=y] && (ARCH_QCOM || SOC_IMX5 || COMPILE_TEST [=y]) && COMMON_CLK [=y] && IOMMU_SUPPORT [=y] && (QCOM_OCMEM [=n] || QCOM_OCMEM [=n]=n) && (QCOM_LLCC [=y] || QCOM_LLCC [=y]=n) && (QCOM_COMMAND_DB [=n] || QCOM_COMMAND_DB [=n]=n)
Make DRM_DP_AUX_BUS depends on OF || COMPILE_TEST to fix this warning.
Fixes: 1e0f66420b13 ("drm/display: Introduce a DRM display-helper module")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220611041612.1976-1-yuehaibing@huawei.com
We don't actually care about connection_mutex here anymore, so let's get rid of the comment mentioning it in this function's kdocs. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Wayne Lin <Wayne.Lin@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220602201757.30431-4-lyude@redhat.com
Drive-by cleanup, we don't need to validate the port references here as we already previously went through the effort of refactoring things such that we're guaranteed to be able to access ->mstb and ->port safely from drm_dp_check_and_send_link_address(), since the only two places in the codebase that drop an MST reference in such a way that it would remove it from the topology are both protected under probe_lock. Thanks for that, past Lyude! Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Wayne Lin <Wayne.Lin@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220602201757.30431-2-lyude@redhat.com
there is an unexpected word "the" in the comments that need to be dropped file: drivers/gpu/drm/display/drm_dp_helper.c line: 1600 * Doesn't account the the "MOT" bit, and instead assumes each changed to * Doesn't account the "MOT" bit, and instead assumes eac Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220621190055.8323-1-jiangjian@cdjrlc.com
drm_crtc.h has no need for drm_edid.h, so don't include it. Avoids useless rebuilds of the entire universe when touching drm_edid.h. Quite a few placs do currently depend on drm_edid.h without actually including it directly. All of those need to be fixed up. v2: Fix up i915 and msm some more v3: Fix alphabetical ordering (Sam) Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220614090245.30283-1-ville.syrjala@linux.intel.com Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Jani Nikula <jani.nikula@intel.com>
Backmerging to get new regmap APIs of v5.19-rc1. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
The WD22TB4 Thunderbolt dock at least will revert its DP_MAX_LINK_RATE from HBR3 to HBR2 after system suspend/resume if the DP_DP13_DPCD_REV registers are not read subsequently also as required. Fix this by reading DP_DP13_DPCD_REV registers as well, matching what is done during connector detection. While at it also fix up the same call in drm_dp_mst_dump_topology(). Cc: Lyude Paul <lyude@redhat.com> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5292 Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Cc: <stable@vger.kernel.org> # v5.14+ Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220614094537.885472-1-imre.deak@intel.com