Bug 108915 - [ICL] Trying to use non-existent 6th (F) DDI port
Summary: [ICL] Trying to use non-existent 6th (F) DDI port
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: DRI git
Hardware: Other All
: high normal
Assignee: Imre Deak
QA Contact: Intel GFX Bugs mailing list
Whiteboard: Triaged
Depends on:
Reported: 2018-11-30 17:01 UTC by Imre Deak
Modified: 2019-02-02 09:31 UTC (History)
1 user (show)

See Also:
i915 platform: ICL
i915 features: display/Other


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Description Imre Deak 2018-11-30 17:01:46 UTC
Some ICL SKUs support only 5 DDI ports (2 combo-PHY and 3 MG PHY) instead of the maximum of 6 ICL supports. We need a way to detect these SKUs based either on VBT or the PCI ID and prevent using the non-existent port.

SKL-Y is one such system, where this problem results in the following error whenever trying to use the non-existent port F:

<7>[   10.710403] [drm:intel_power_well_enable [i915]] enabling AUX F
<4>[   10.711756] ------------[ cut here ]------------
<4>[   10.711760] WARN_ON(intel_wait_for_register(dev_priv, regs->driver, (0x1 << ((pw_idx) * 2)), (0x1 << ((pw_idx) * 2)), 1))

One example:
Comment 1 Lakshmi 2018-12-03 09:04:04 UTC
Is this bug duplicate of https://bugs.freedesktop.org/show_bug.cgi?id=108070 ?
Comment 2 Jani Saarinen 2018-12-03 09:14:03 UTC
T hink no, but let Imre to confirm
Comment 3 Imre Deak 2018-12-03 11:03:40 UTC
Not a duplicate, the root cause of this is described in the description of this bug, while the root cause of the other is described at
Comment 4 Lakshmi 2018-12-03 17:56:05 UTC
This issue is reported to BIOS team.
Comment 5 Jani Saarinen 2018-12-07 09:38:06 UTC
No updates yet.
Comment 6 Jani Saarinen 2018-12-20 15:37:27 UTC
Ref to WA: https://patchwork.freedesktop.org/series/54341/
Comment 7 Jani Saarinen 2019-01-31 17:13:57 UTC
Was this merged today Imre?
Comment 8 Imre Deak 2019-01-31 17:42:31 UTC
(In reply to Jani Saarinen from comment #7)
> Was this merged today Imre?


commit 2b34e562361f6e440524272187432c551b57481e
Author: Imre Deak <imre.deak@intel.com>
Date:   Thu Dec 20 17:52:11 2018 +0200

    drm/i915/icl: Work around broken VBTs for port F detection

I think we can close this now even though for a proper solution we'll want to have the VBT fixed eventually.

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