[PATCH 0/2][SRU][G] Support WD19TB external output on TGL platform

[Hsuan-Yu Lin]

BugLink: https://bugs.launchpad.net/bugs/1886165

[Impact]
TGL platform can't output external monitor on WD19TB docking.
There's no screen on the external monitor.
error in dmesg:

[drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underru

[Fix]
According to Intel's suggestion,
we need this: https://patchwork.freedesktop.org/series/78909/
The following patches are landed in 5.9-rc1
and necessary for support TGL platform:

* commit 09eac8277262 ("drm/i915/tgl+: Fix TBT DPLL fractional divider for 38.4MHz ref clock")
* commit f153478de4b2 ("drm/i915/tgl+: Use the correct DP_TP_* register instances in MST encoders")

[Test]
The WD19TB can output HDMI/DP to external monitor.

[Regression Potential]
Low, it's the fixes for TGL platform, doesn't affect other platforms.

Imre Deak (2):
  drm/i915/tgl+: Use the correct DP_TP_* register instances in MST
    encoders
  drm/i915/tgl+: Fix TBT DPLL fractional divider for 38.4MHz ref clock

 drivers/gpu/drm/i915/display/intel_ddi.c      | 15 ++++++++++-----
 drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 13 ++++++++++++-
 2 files changed, 22 insertions(+), 6 deletions(-)

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2.25.1