1601682 - Allow more than 16 samples with the Mesa driver

Status: RESOLVED DUPLICATE of bug 1603843

(Core :: Graphics: CanvasWebGL, enhancement, P1)

Description

[Kristian Klausen]

Hi

I can't play Airmash as it use more than 16 samplers, if I set gfx.work-around-driver-bugs = false I can play the game without any issue.

I did some research and WebGL programs with more than 16 samplers was disabled for the Mesa driver 7+ years ago due to a bug in the driver. If I intercept the the original bug report correctly, the issue was fixed in this Mesa commit 7 years ago.

According to the original bug report, it didn't matter that the Mesa version wasn't checked as a "it is unlikely that a legitimate real-world page would use more than 16 samplers in a program.":
(In reply to Mike Hommey [:glandium] (high latency) from comment #82)

(In reply to Benoit Jacob [:bjacob] from comment #71)

http://hg.mozilla.org/releases/mozilla-esr10/rev/68691b2f1eda

FWIW, that was overly broad. versions < 8 are not affected.

(In reply to Benoit Jacob [:bjacob] (mostly away) from comment #83)

Doesn't matter much, it is unlikely that a legitimate real-world page would
use more than 16 samplers in a program.

Relevant OS info:
Application Basics

Name: Firefox
Version: 72.0a1
Build ID: 20191202091209
Update Channel: nightly
User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:72.0) Gecko/20100101 Firefox/72.0
OS: Linux 5.4.1-arch1-1
Multiprocess Windows: 1/1 Enabled by default
Remote Processes: 10
Safe Mode: false

Graphics

Features
Compositing: WebRender
GPU #1
Active: Yes
Description: Mesa DRI Intel(R) UHD Graphics 620 (Kabylake GT2)
Vendor ID: 0x8086
Device ID: 0x5917
Driver Vendor: mesa/i965
Driver Version: 19.2.6.0
RAM: 3072

Comment 1

[Kristian Klausen]

BTW: The workaround added in #1203135(hg) also seems to be unneeded these days. I can't crash my browser with the test files in that bug.

Comment 2

[Kelsey Gilbert [:jgilbert]]

Yeah, we can relax this.