[Intel-gfx] [PATCH] drm: Aggressively disable vblanks

Keith Packard keithp at keithp.com
Mon Dec 20 19:23:40 PST 2010

On Mon, 20 Dec 2010 14:00:54 -0500, Andy Lutomirski <luto at MIT.EDU> wrote:

> Enabling and disabling the vblank interrupt (on devices that
> support it) is cheap.  So disable it quickly after each
> interrupt.

So, the concern (and reason for the original design) was that you might
lose count of vblank interrupts as vblanks are counted differently while
off than while on. If vblank interrupts get enabled near the interrupt
time, is it possible that you'll end up off by one somehow?

Leaving them enabled for 'a while' was supposed to reduce the impact of
this potential error.

keith.packard at intel.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20101220/105a9fb6/attachment.pgp>

More information about the dri-devel mailing list