[Bug 108885] New: Parade LSPCON Scrambling Failure

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108885

            Bug ID: 108885
           Summary: Parade LSPCON Scrambling Failure
           Product: DRI
           Version: DRI git
          Hardware: Other
                OS: All
            Status: NEW
          Severity: normal
          Priority: medium
         Component: DRM/Intel
          Assignee: intel-gfx-bugs at lists.freedesktop.org
          Reporter: swati2.sharma at intel.com
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
                CC: intel-gfx-bugs at lists.freedesktop.org

There is an issue which we are observing with Parade LSPCON on KBL NUCs. Parade
LSPCON forgets to turn off scrambling/bit clock rate when switching from a mode
that needs them to a mode that does not. This manifests as a "no signal"
followed by black screen on TV when tried to go from 4k to 1080p for example.
If SCDC register manually poked over DDC, picture appears.
Here's the OUI/fw revision for the LSPCON chip in question:
DP branch: OUI 00-1c-f8 dev-ID 175IB0 HW-rev 1.0 SW-rev 7.32 quirks 0x0000
Connector Info:
DP branch device present: yes
Type: HDMI
ID: 175IB0
HW: 1.0
SW: 7.32
Max TMDS clock: 600000 kHz
Max bpc: 12

Issue has also been reproduced on KBL RVP + LSPCON chip as an external adaptor.
OUI/fw revision for the LSPCON chip:
DP branch: OUI 00-1c-f8 dev-ID 175IB0 HW-rev 1.2 SW-rev 7.35 quirks 0x0000
Connector Info:
DP branch device present: yes
Type: HDMI
ID: 175IB0
HW: 1.2
SW: 7.35
Max TMDS clock: 600000 kHz
Max bpc: 12

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