From: Emil Velikov <emil.velikov@xxxxxxxxxxxxx> Currently as the workaround is applied the screen flickers. As a result we do not achieve seamless boot experience. Avoiding the issue in the common use-case might be hard, although we can resolve it for dual GPU setups - when the "other" GPU is primary and/or outputs are connected to it. With this I was able to get seamless experience on my Intel/Nvidia box, running systemd-boot and sddm/Xorg. Note that the i915 driver is within initrd while the Nvidia one is not. Without this patch, the splash presented by systemd-boot (UEFI BGRT) is torn down as the code-path kicks in, leaving the monitor blank until the login manager starts. Same issue were reported with plymouth/grub, although personally I wasn't able to get them to behave on my setup. Suggested-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Emil Velikov <emil.velikov@xxxxxxxxxxxxx> --- Supersedes https://lore.kernel.org/dri-devel/20210516171432.1734268-1-emil.l.velikov@xxxxxxxxx/ Ville, others, Patch is based against drm-intel/drm-intel-next and will apply cleanly against drm-intel/drm-intel-fixes. If possible, can one of the i915 maintainers apply it to the latter? Thanks Emil --- drivers/gpu/drm/i915/display/intel_vga.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index be333699c515..7beef1206097 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -29,6 +29,9 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) i915_reg_t vga_reg = intel_vga_cntrl_reg(dev_priv); u8 sr1; + if (intel_de_read(dev_priv, vga_reg) & VGA_DISP_DISABLE) + return; + /* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO); outb(SR01, VGA_SR_INDEX); -- 2.31.1
