On Fri, 4 Jun 2021 at 16:49, Emil Velikov emil.l.velikov@gmail.com wrote:

From: Emil Velikov emil.velikov@collabora.com

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@linux.intel.com Signed-off-by: Emil Velikov emil.velikov@collabora.com

---

Supersedes https://lore.kernel.org/dri-devel/20210516171432.1734268-1-emil.l.velikov@gm...

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

Humble poke?

-Emil