# Re: \[PATCH 2/5\] OMAPFB: simplify locking

- From: Tomi Valkeinen \<hidden\>
- Date: 2012-12-13 11:17:17 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2012/12/13464481
- Thread: https://ratatoskr.run/linux-omap/2012/12/13464520/t.md

```text
On 2012-12-07 13:55, Tomi Valkeinen wrote:
> Kernel lock verification code has lately detected possible circular
> locking in omapfb. The exact problem is unclear, but omapfb's current
> locking seems to be overly complex.
> 
> This patch simplifies the locking in the following ways:
> 
> - Remove explicit omapfb mem region locking. I couldn't figure out the
>   need for this, as long as we take care to take omapfb lock.
> 
> - Get omapfb lock always, even if the operation is possibly only related
>   to one fb_info. Better safe than sorry, and normally there's only one
>   user for the fb so this shouldn't matter.
> 
> - Make sure fb_info lock is taken first, then omapfb lock.
> 
> With this patch the warnings about possible circular locking does not
> happen anymore.

I'm dropping this patch, for some reason it causes huge latencies with
two processes using separate fbs. I guess there's need for the more
precise locking, after all.

 Tomi


```

## Attachments

- [signature.asc](https://ratatoskr.run/linux-fbdev/2012/12/13464481/attachment/0) (application/pgp-signature, 899 bytes)