Bug 85158 - Glyph rendering corruption in Firefox tabs [SNA]
Summary: Glyph rendering corruption in Firefox tabs [SNA]
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: git
Hardware: Other All
: medium normal
Assignee: Chris Wilson
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-10-17 21:47 UTC by Clemens Eisserer
Modified: 2014-10-20 20:28 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments
screenshot of the issue (21.04 KB, text/plain)
2014-10-17 21:47 UTC, Clemens Eisserer
no flags Details
screenshot of the issue (21.04 KB, image/png)
2014-10-17 21:48 UTC, Clemens Eisserer
no flags Details
Apply gen7 flushes to gen6 (5.56 KB, patch)
2014-10-18 10:00 UTC, Chris Wilson
no flags Details | Splinter Review
Apply gen7 flushes to gen6, v2 (6.93 KB, patch)
2014-10-20 08:11 UTC, Chris Wilson
no flags Details | Splinter Review

Description Clemens Eisserer 2014-10-17 21:47:56 UTC
Created attachment 108008 [details]
screenshot of the issue

For some time I now I seldomly experience glyph corruption on my Sandy Bridge Laptop using SNA in Firefox's Tab header when choosing "Open Link in New Tab" in a Link's context menu. The issue seems to trigger more frequently when pages build their content dynamically.
Comment 1 Clemens Eisserer 2014-10-17 21:48:58 UTC
Created attachment 108009 [details]
screenshot of the issue
Comment 2 Clemens Eisserer 2014-10-17 21:59:25 UTC
Seems to be triggerd by RGB glyphs, haven't been able to reproduce the bug with grayscale antialiasing so far.

Kernel: 3.16.6
Intel: 2.99.916-102-g6b98f16
Comment 3 Chris Wilson 2014-10-18 10:00:17 UTC
Created attachment 108026 [details] [review]
Apply gen7 flushes to gen6

May or may not fix the issue, worth a shot.

Otherwise please try each of

#define ALWAYS_INVALIDATE 0
#define ALWAYS_FLUSH 0
#define ALWAYS_STALL 0

and see if any are useful.
Comment 4 Clemens Eisserer 2014-10-19 14:22:28 UTC
You patch seems to have fixed the issue, haven't been able to observe it with manual testing. I'll report back in case it appears again.
Thanks!
Comment 5 Chris Wilson 2014-10-20 08:11:28 UTC
Created attachment 108088 [details] [review]
Apply gen7 flushes to gen6, v2

I rearranged the patch slightly, so it would be good to retest since the flushing is subtle and can be quick to anger.
Comment 6 Chris Wilson 2014-10-20 20:28:45 UTC
Fingers crossed:

commit 316155db98aac4d5d0a7077e86453e4d41a3029d
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sat Oct 18 10:58:03 2014 +0100

    sna/gen6: Apply gen7 flushing
    
    Clemens Eisserer noticed that glyphs would randomly disapper whilst
    being rendered on his Sandybridge, a sign that the GPU is not flushing
    its internal state on pipeline changes. As a precaution, adopt the
    Ivybridge flush semantics (whilst preserving the required Sandybridge
    workarounds).
    
    Reported-and-tested-by: Clemens Eisserer <linuxhippy@gmail.com>
    Reported-and-tested-by: Ilia Mirkin <imirkin@alum.mit.edu>
    References: https://bugs.freedesktop.org/show_bug.cgi?id=85158
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>


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