From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gerd Hoffmann <kraxel@redhat.com>
Subject: Re: bochs_hw_init fails to request framebuffer on EFI boot with
 plymouth visible
Date: Wed, 15 Jan 2020 15:13:53 +0100
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To: Marek =?utf-8?Q?Marczykowski-G=C3=B3recki?= <marmarek@invisiblethingslab.com>
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  Hi,

> > And "grep -A1 0000:00:02.0 /proc/iomem" ?
> 
>   c0000000-c0ffffff : 0000:00:02.0
>   c1000000-c103ffff : 0000:00:04.0

So no reservation left.  Whatever blocked the pci bar resource (efifb
probably) is gone now.

So the interesting question is why that reservation sticked long enough
to prevent bochs-drm from initializing.  In theory efifb de-init should
be completed when drm_fb_helper_remove_conflicting_pci_framebuffers()
returns.

Bisecting could help, or springkling printk's into efifb ...

> [46921.562805] fbcon: bochs-drmdrmfb (fb0) is primary device
> [46921.562808] fbcon: Deferring console take-over

I think that is just some eye candy which delays fbcon init until
something is actually printed.

Try "echo hello world > /dev/tty0".
Maybe tapping enter (to make getty re-print the login prompt) works too.

cheers,
  Gerd