#15410: VESA drvier picks up other drivers mode
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Reporter: nephele | Owner: nobody
Type: bug | Status: new
Priority: normal | Milestone: Unscheduled
Component: Drivers/Graphics/VESA | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking:
Has a Patch: 0 | Platform: All
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Comment (by pulkomandy):
You can always force a specific videomode for the VESA driver from the
bootmenu at least, so it should not prevent getting back your display in
any case.
That VESA tries to use the same mode as the other driver if available is a
feature, we do our best to provide a native resolution bootscreen. Why
would we not do that?
As usual with VESA, we can't do much but blindly trust the VESA BIOS in
what it tells it supports. If it says it has a 1600x1200 mode, we have no
way to know if that's usable or not, so we will just try it. We do some
filtering by asking the display itself for its EDID info (which VESA
allows us to access), but still, a few things can go wrong:
- The VESA BIOS pretends to support a 1600x1200 mode, but it is in fact
non-working or the timings are not the one it tells us it would use, and
it ends up being out of range of monitor capabilities,
- The monitor is not giving correct EDID info, so we think the mode should
work according to what it says, but it in fact doesn't handle it.
There is not much we can do with VESA, it just doesn't give us enough
control on the video timings. We can add quirks for specific VESA BIOS
implementations or known bogus EDID info, but it is really a case by case
thing.
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Ticket URL: <https://dev.haiku-os.org/ticket/15410#comment:2>
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