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| author | Emil Velikov <emil.velikov@collabora.com> | 2021-06-04 16:49:05 +0100 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2021-06-10 17:31:51 +0300 |
| commit | a3af0140663dc335e5c18277a61bb99bfcb60694 (patch) | |
| tree | c8bf71a96783f470be9451e32a98e409cec1ec35 /drivers/gpu/drm/i915/display/intel_vga.c | |
| parent | 0d6695b112762aa7aad28c46e65561389b6f50d6 (diff) | |
| download | linux-a3af0140663dc335e5c18277a61bb99bfcb60694.tar.gz linux-a3af0140663dc335e5c18277a61bb99bfcb60694.tar.bz2 linux-a3af0140663dc335e5c18277a61bb99bfcb60694.zip | |
drm/i915: apply WaEnableVGAAccessThroughIOPort as needed
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>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210604154905.660142-1-emil.l.velikov@gmail.com
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_vga.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_vga.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index f002b82ba9c0..3385b45ecd4b 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); |