Parade LSPCON Scrambling Failure

Submitted by Swati2 Sharma @swati2.sharma

Assigned to Swati2 Sharma @swati2.sharma

Link to original bug (#108885)

Description

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