# Re: 3.8-rc2: EFI framebuffer lock inversion...

- From: Alan Cox \<hidden\>
- Date: 2013-01-03 13:05:25 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2013/01/3977945
- Thread: https://ratatoskr.run/linux-fbdev/2013/01/3977941/t.md

```text
On Thu, 3 Jan 2013 20:56:30 +0800
Daniel J Blueman [ref] wrote:

> On 3.8-rc2 with lockdep enabled and dual-GPU setup (Macbook Pro
> Retina), I see two releated lock inversion issues with the EFI
> framebuffer, leading to possible deadlock: when X takes over from the
> EFI framebuffer [1] and when nouveau releases the framebuffer when
> being vgaswitcherood [2].
> 
> Let me know if you'd like any testing or analysis when I can get the time.

The fb layer locking was broken. I posted patches early December which
should have fixed the ones we know about. ('fb: Rework locking to fix
lock ordering on takeover').

Alan
```