On Sun, May 16, 2021 at 06:14:32PM +0100, Emil Velikov wrote:
From: Vivek Das Mohapatra vivek@collabora.com
This patch is to do with seamless handover, eg when the sequence is bootloader → plymouth → desktop.
It switches the vga arbiter from the "other" GPU to the default one (intel in this case), so the driver can issue some io().
I don't understand what this commit message is trying to say.
Signed-off-by: Vivek Das Mohapatra vivek@collabora.com Signed-off-by: Emil Velikov emil.velikov@collabora.com
Greetings all,
This patch has been downstream for a while now yet it seems perfectly reasonable thing to have in the Linux kernel.
https://github.com/ValveSoftware/steamos_kernel/commit/5431b5b1999c3d3b5efee...
drivers/gpu/drm/i915/display/intel_vga.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index be333699c515..4f07b5ad5fa0 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -30,12 +30,14 @@ void intel_vga_disable(struct drm_i915_private *dev_priv) u8 sr1;
/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */
- vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
- outb(SR01, VGA_SR_INDEX);
- sr1 = inb(VGA_SR_DATA);
- outb(sr1 | 1 << 5, VGA_SR_DATA);
- vga_put(pdev, VGA_RSRC_LEGACY_IO);
- udelay(300);
if (pdev == vga_default_device()) {
vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);outb(SR01, VGA_SR_INDEX);sr1 = inb(VGA_SR_DATA);outb(sr1 | 1 << 5, VGA_SR_DATA);vga_put(pdev, VGA_RSRC_LEGACY_IO);udelay(300);}
intel_de_write(dev_priv, vga_reg, VGA_DISP_DISABLE); intel_de_posting_read(dev_priv, vga_reg);
-- 2.27.0