#13669: Intel HD Graphics 2500 black screen on VGA out
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Reporter: vidrep | Owner: rudolfc
Type: bug | Status: in-progress
Priority: normal | Milestone: R1
Component: | Version:
Drivers/Graphics/intel_extreme/ivybridge | R1/Development
Resolution: | Keywords:
Blocked By: | Blocking:
Platform: All |
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Comment (by rudolfc):
Ah yes, that's correct. I saw something myself as well: I re-enabled the
default modeline setup from this driver, where for 1920x1080 I had a
'tighter' modeline (from my own screen) in the driver.
Both should work of course -but- the default line @60Hz requires 3 lanes,
where 'my' line just 2. Since the BIOS sets it up for the native modeline
from your screen, and that's apparantly also tigher than Haiku's default
modeline: therefore the BIOS sets 2 lanes.
The fact that the driver would need 3 lanes @60Hz makes the distortion
happen. at the lower refresh the mode 'fits' in 2 lanes and therefore it
works OK.
See this line in your syslog:
KERN: intel_extreme: Train: FDI Link Lanes: 3
When you try to set 60Hz.
Are you able to do a test for that screen using a digital connection
instead of the analog one? If so, I'd like to know how that works out. Be
warned though: the same limitations (more or less) apply there. So set a
lower mode than 1920x1080, or see if you can set 55Hz or so..
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Ticket URL: <https://dev.haiku-os.org/ticket/13669#comment:38>
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