ma1 pushed to branch tor-browser-140.5.0esr-15.0-1 at The Tor Project / Applications / Tor Browser Commits: f69a12e8 by Jamie Nicol at 2025-11-21T22:03:59+01:00 Bug 1941154 - Use shader to clear alpha targets on Adreno 510. a=diannaS DONTBUILD Recent refactoring of render target initialization caused stale contents of alpha render targets to be used as clip masks instead of valid masks on Adreno 510 devices. Presumably we were fortunate not to be hitting this previously, and it was regressed by a subtle accidental behavioural change introduced by the refactor. Using quads to clear alpha targets appears to be the most robust way of avoiding it. Original Revision: https://phabricator.services.mozilla.com/D260105 Differential Revision: https://phabricator.services.mozilla.com/D260301 - - - - - 1 changed file: - gfx/wr/webrender/src/device/gl.rs Changes: ===================================== gfx/wr/webrender/src/device/gl.rs ===================================== @@ -1819,7 +1819,10 @@ impl Device { // On Mali-Txxx devices we have observed crashes during draw calls when rendering // to an alpha target immediately after using glClear to clear regions of it. // Using a shader to clear the regions avoids the crash. See bug 1638593. - let supports_alpha_target_clears = !is_mali_midgard(&renderer_name); + // On Adreno 510 devices we have seen garbage being used as masks when clearing + // alpha targets with glClear. Using quads to clear avoids this. See bug 1941154. + let is_adreno_510 = renderer_name.starts_with("Adreno (TM) 510"); + let supports_alpha_target_clears = !is_mali_midgard(&renderer_name) && !is_adreno_510; // On Adreno 4xx devices with older drivers we have seen render tasks to alpha targets have // no effect unless the target is fully cleared prior to rendering. See bug 1714227. View it on GitLab: https://gitlab.torproject.org/tpo/applications/tor-browser/-/commit/f69a12e8... -- View it on GitLab: https://gitlab.torproject.org/tpo/applications/tor-browser/-/commit/f69a12e8... You're receiving this email because of your account on gitlab.torproject.org.