XPost: linux.debian.bugs.dist   
   From: jarl.gullberg@visar-systems.com   
      
   Source: linux   
   Severity: wishlist   
      
   Dear Maintainer,   
      
   Currently, Debian does not enable CONFIG_DRM_SIMPLEDRM or   
   CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER by default. I'd like to   
   request that these config options be enabled for UEFI-enabled   
   architectures in order to better support flicker-free boot.   
      
   CONFIG_DRM_SIMPLEDRM enables a simple DRM driver for   
   platform-provided framebuffers. The driver is primarily useful for   
   lightweight graphics handling before heavier drivers have loaded (such   
   as NVIDIA or AMD drivers) and vendor-agnostic early-boot framebuffer   
   handling.   
      
   Specifically, this is the default choice for early-boot splash programs   
   like Plymouth. Using SimpleDRM removes the need for the system   
   administrator to explicitly load any vendor-specific modules in the   
   initrd or increase timeouts in Plymouth to compensate for longer load   
   times of larger drivers.   
      
   CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER defers the clearing of the   
   framebuffer console until the first text is displayed on the console.   
   Without this option, there is a brief time between the firmware   
   splash screen and the initialization Plymouth splash screen where the   
   kernel may clear the graphics from the firmware.   
      
   When booting with "quiet", this will result in a black flicker between   
   the UEFI firmware and Plymouth. Without "quiet", text output is briefly   
   visible as expected.   
      
   By enabling the deferred takeover, the graphics from the firmware can   
   remain in the framebuffer until either a) the kernel begins printing   
   text or b) Plymouth (or similar software) takes control and does   
   whatever it's been configured to do. In cases where flicker-free boot is   
   desired, that would typically be reusing the BGRT graphics in the   
   framebuffer and overlaying or augmenting it with additional elements   
   like a loading spinner.   
      
   SimpleDRM is not a hard requirement for flicker-free boot, but it does   
   help significantly when building configurations not tied to a single   
   vendor. Deferred takeover, on the other hand, is required for the   
   aforementioned reasons.   
      
   Other distributions have already used both options for a while in stable   
   configurations (Fedora, NixOS, Red Hat, OpenSUSE, Arch Linux, etc.), so   
   I believe the change would be relatively low-impact. There were some   
   concerns around combining GRUB and deferred takeover, but I believe that   
   was fixed back in 2018 by Fedora.   
      
   -- System Information:   
   Debian Release: 13.2   
     APT prefers stable-updates   
     APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500,   
   'stable')   
   Architecture: amd64 (x86_64)   
      
   Kernel: Linux 6.12.57+deb13-amd64 (SMP w/2 CPU threads; PREEMPT)   
   Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=locale: Cannot set   
   LC_ALL to default locale: No such file or directory   
   UTF-8), LANGUAGE=en_US:en   
   Shell: /bin/sh linked to /usr/bin/dash   
   Init: systemd (via /run/systemd/system)   
   LSM: AppArmor: enabled   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)