Bug 108885 - Parade LSPCON Scrambling Failure
Summary: Parade LSPCON Scrambling Failure
Status: REOPENED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: DRI git
Hardware: Other All
: medium normal
Assignee: Swati Sharma
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard: Triaged, ReadyForDev
Keywords:
Depends on:
Blocks:
 
Reported: 2018-11-28 10:35 UTC by Swati Sharma
Modified: 2018-12-05 11:49 UTC (History)
1 user (show)

See Also:
i915 platform: KBL
i915 features: display/LSPCON


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Description Swati Sharma 2018-11-28 10:35:57 UTC
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
Comment 1 Swati Sharma 2018-12-04 14:25:02 UTC
Issue is resolved after getting the latest fw from parade (SW:7.64)
Testing done on KBL NUC. Resolving->Closing.
Comment 2 Ville Syrjala 2018-12-04 19:45:01 UTC
If we don't have a Linux firmware flasher that can be used by normal people this is still a problem.
Comment 3 Jani Saarinen 2018-12-05 11:49:42 UTC
Agree, we can update on CI but cannot close until FW available for masses.


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