peter fuerst wrote:
Why does it need that flush?
To prepare the update-area (in the Shadow-FB) for DMA to RE.
And on systems where the root frame buffer is directly manipulated by
the CPU, the video system is continually using DMA to refresh the
display. A cache flush can be required to eliminate transient visual
glitches.
David Daney
kind regards
On Fri, 13 Feb 2009, Ralf Baechle wrote:
Date: Fri, 13 Feb 2009 23:56:03 +0000
From: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
To: peter fuerst <post@xxxxxxxx>
Cc: naresh kamboju <naresh.kernel@xxxxxxxxx>, linux-mips@xxxxxxxxxxxxxx
Subject: Re: cacheflush system call-MIPS
On Sat, Feb 14, 2009 at 12:50:46AM +0100, peter fuerst wrote:
there is one more good reason to ... : the Impact Xserver needs to do
a cacheflush(a,w,DCACHE) as part of the refresh-sequence.
And hence requires a sys_cacheflush, let's say, more conforming to the
man-page (or some disgusting new ioctl in the Impact kernel-driver to
do an equivalent operation ;-)
Why does it need that flush?
Ralf
