(In reply to Lee Salzman [:lsalzman] from comment #25) > The circumstantial evidence "seems like" something in the function here > (https://searchfox.org/mozilla-central/source/gfx/wr/swgl/src/composite.h#534) > is underflowing. But I would need someone who can reliably reproduce the > issue to find out where in those math equations are actually doing so. I > tried testing in my patch if the additions were the culprit, but that seems > unlikely. > > It's possible the multiplications "rbCoeffs * uv" or "gCoeffs * uv" are > underflowing based on whatever values the ARM video codecs seem to be > supplying. However, this is not happening on x86 at all, which is strange, > and it is also happening on ARM across platform, which is further strange, > since there isn't really much in the way of platform specific code here. > > Sotaro, might you be able to investigate this?
Taking a step back. If a certain function is suspected what are the diff's with this code between the working 88.0 and non working 89.0 version? Since the issue affects all ARM regardless of platform the only culprit not eliminated is Firefox. If you have a downloaded executable for me to test I'm happy to do so. My platforms are : aarch64 Ubuntu 18.04 LTS aarch64 Ubuntu 20.10 I can only test on one of these platforms! -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1930982 Title: Firefox 89: webrender breaks videos on Raspberry Pi Status in Mozilla Firefox: Fix Released Status in firefox package in Ubuntu: Fix Released Bug description: Firefox 89 enabled the Webrender framework by default. Unfortunately, the GFX drivers on a Pi 4 seem to be non-compliant in a way that breaks videos - specifically, there will be a lot of primary coloured artefacts in videos. My guess is that other Raspberry Pi's will also be affected, but I don't have the hardware available to test. Setting gfx.webrender.force-disabled to True fixes the issue, so it's fairly clear where it lies. Mozilla doesn't seem to provide official builds for Raspberry Pi's (or Linux/Arm in general), so I think this is an issue to fix in these packages, rather than upstream. The quick solution would to just set gfx.webrender.force-disabled to True for the Pi-platforms and be done with it, but there may be better solutions I don't know about. Additioal info: Ubuntu release: 21.04 Firefox package: firefox/hirsute-security,hirsute-updates,now 89.0+build2-0ubuntu0.21.04.1 arm64 Steps to reproduce: Play a video on Youtube, watch the coloured blocks appear. Then set gfx.webrender.force-disabled to True and restart to verify the fix. To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1930982/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
