Bugzilla – Bug 42943
[IVB] Boot with a vga monitor can't light the DP screen while plugin it
Last modified: 2012-04-15 19:28:31 UTC
Created attachment 53567 [details]
the log from intel_reg_dumper
While we boot only with monitor connnect to VGA,then we plug in DP port,the DP screen turn to be black.if we unplug the DP monitor, the VGA monitor can display normally.
BTW,if we boot with Dp monitor and plug in a VGA port,the DP screen will turn to be black,and the VGA monitor can display normally.Meanwhile, if we unplug the VGA monitor, the DP monitor will still be black.
1, boot up system with VGA monitor only
2, plug in a Dp monitor
1, boot up system with Dp monitor only
2, plug in a VGA monitor
dmesg information is only the error :
[drm:pch_irq_handler] *ERROR* PCH poison interrupt
so I add the log from intel_reg_dumper .
Maybe related bug 44305.
Created attachment 56179 [details] [review]
fixup dp bpc calculations
Can you pleast try this patch?
(In reply to comment #2)
> Created attachment 56179 [details] [review] [review]
> fixup dp bpc calculations
> Can you pleast try this patch?
This patch can resolve this problem with latest drm-intel-testing.
Author: Keith Packard <firstname.lastname@example.org>
Date: Wed Jan 25 08:16:25 2012 -0800
drm/i915: Force explicit bpp selection for intel_dp_link_required
It is never correct to use intel_crtc->bpp in intel_dp_link_required,
so instead pass an explicit bpp in to this function. This patch
only supports 18bpp and 24bpp modes, which means that 10bpc modes will
be computed incorrectly. Fixing that will require more extensive
changes, and so must be addressed separately from this bugfix.
intel_dp_link_required is called from intel_dp_mode_valid and
* intel_dp_mode_valid is called to list supported modes; in this case,
the current crtc values cannot be relevant as the modes in question
may never be selected. Thus, using intel_crtc->bpp is never right.
* intel_dp_mode_fixup is called during mode setting, but it is run
well before ironlake_crtc_mode_set is called to set intel_crtc->bpp,
so using intel_crtc-bpp in this path can only ever get a stale
Cc: Lubos Kolouch <email@example.com>
Cc: Adam Jackson <firstname.lastname@example.org>
Reviewed-by: Daniel Vetter <email@example.com>
Tested-by: Dave Airlie <firstname.lastname@example.org>
Tested-by: email@example.com (Dell Latitude 6510)
Tested-by: Roland Dreier <firstname.lastname@example.org>
Signed-off-by: Keith Packard <email@example.com>
tested by guang yang, the -fixes branch contains this patch.