Sent out today was the latest batch of drm-intel-next changes as feature work toward DRM-Next for Linux 7.1 winds down. This week’s drm-intel-next pull is mostly fixes and some low-level code refactoring. The only item really standing out is some new quirk infrastructure for dealing with laptop display panels that may have buggy Panel Replay handling.
VESA Panel Replay provides power-savings with capable displays using DisplayPort 2.0+ / eDP 1.5+. The power savings come by only updating portions of the screen that actively change rather than refreshing the entire panel. Panel Replay works better than the prior Panel Self Refresh (PSR) tech while now there’s been new hardware that hasn’t been working out well with Panel Replay and thus for now the need has come to have quirk infrastructure in the Intel driver to allow disabling select problematic laptops / panels.
The problem surfaced with a bug report a few weeks ago over window drags becoming laggy after resuming from suspend with an OLED panel on a Dell XPS 14 Panther Lake laptop. Intel Linux driver engineers ultimately tracked down the issue to being with the Panel Replay functionality with the Dell XPS 14 Core Ultra Series 3 laptop with a particular panel. But making it more troubling is that the same panel ended up working fine without issue in another laptop model.
Today’s drm-intel-next pull for Linux 7.1 thus introduces a new “QUIRK_DISABLE_PANEL_REPLAY” quirk to allow selectively disabling Panel Replay based on laptop model and display panel. This patch lays out that new quirk handling with so far just applying to the Dell XPS 14 DA14260 with the problematic OLED panel will have this power-savings feature disabled by default, at least until the underlying issue can be sorted out. A follow-up patch is also part of this week’s pull request due to Dell changing the device ID even within the same device model.
So for those that may happen to have a new Dell XPS 14 Panther Lake laptop and experiencing window drags becoming laggy or similar behavior, this workaround to disable Panel Replay by default will be part of the upcoming Linux 7.1 merge window.
The full list of drm-intel-next patches part of this latest pull request for DRM-Next / Linux 7.1 can be found via this pull request.
Source: https://www.phoronix.com/news/Intel-Linux-7.1-Panel-Replay