Bug 6762

Summary:

Radeon may have excessive cache flushing

Product:

xorg

Reporter:

Eric Anholt <eric>

Component:

Driver/Radeon

Assignee:

Xorg Project Team <xorg-team>

Status:

RESOLVED FIXED

QA Contact:

Severity:

normal

Priority:

high

CC:

alexdeucher, benh

Version:

git

Keywords:

patch

Hardware:

x86 (IA32)

OS:

FreeBSD

Whiteboard:

i915 platform:

i915 features:

Bug Depends on:

6761

Bug Blocks:

Attachments:

Description	Flags
Patch to remove apparently gratuitous cache flushing	none

Description Eric Anholt 2006-04-27 12:04:30 UTC

While dealing with bug #6761, I wrote the patch attached there first, and that
fixed my rendering issues.  Then I noticed I'd missed the SWITCH_TO_*D in
radeon_exa.c, so I tried applying the s/RB2D/RB3D/ there.  The effect I noticed
was reduced performance (~-12%, and my rendering was fine already), so I tried
just removing those lines, to no ill effect.

I suspect that RADEON_WAIT_UNTIL with *_IDLECLEAN deals with triggering the
flushing, even though my reading of the docs before had indicated that it only
waited for a flush to complete (I inferred that the flush had to already be
happening).  I think I saw a minor performance gain from this (~1% in rgb24text,
would need to do some cleaner runs to see).  However, I'm just attaching a patch
since my testing is a sample of one card, with or without DRI, currently.

Comment 1 Eric Anholt 2006-04-27 12:05:02 UTC

Created attachment 5492 [details] [review]
Patch to remove apparently gratuitous cache flushing

Comment 2 Michel Dänzer 2006-07-02 16:27:41 UTC

Pushed to git, thanks.

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