55 lines
1.9 KiB
Diff
55 lines
1.9 KiB
Diff
From c6ce9c635e6576c86c546177c3d770dec2f3c9ae Mon Sep 17 00:00:00 2001
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From: Leah Rowe <info@minifree.org>
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Date: Fri, 23 Feb 2024 13:33:31 +0000
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Subject: [PATCH 1/1] nb/haswell: Disable iGPU when dGPU is used
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This is usually is handled by Haswell mrc.bin, disabling VGA
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decode on the iGPU when a dGPU is installed. However, Broadwell
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mrc.bin does not, so the iGPU and dGPU are both enabled.
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This patch disables legacy VGA cycles for iGPU, under such
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conditions. It has been tested on Broadwell mrc.bin when
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using a graphics card on Dell OptiPlex 9020 SFF (currently
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under review at this time of writing, submitted by Mate
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Kukri).
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This patch has also been tested when Haswell mrc.bin is used,
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and there are seemingly no breaking changes caused by it.
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Change-Id: I1df0a3aa42f8475b7741007bf3e28c2e089d916b
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Signed-off-by: Leah Rowe <info@minifree.org>
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Reviewed-on: https://review.coreboot.org/c/coreboot/+/80717
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Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
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Reviewed-by: Nico Huber <nico.h@gmx.de>
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---
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src/northbridge/intel/haswell/gma.c | 7 +++++++
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1 file changed, 7 insertions(+)
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diff --git a/src/northbridge/intel/haswell/gma.c b/src/northbridge/intel/haswell/gma.c
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index 6e6948b70f..48a0ba54c7 100644
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--- a/src/northbridge/intel/haswell/gma.c
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+++ b/src/northbridge/intel/haswell/gma.c
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@@ -461,12 +461,19 @@ static void gma_generate_ssdt(const struct device *dev)
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drivers_intel_gma_displays_ssdt_generate(&chip->gfx);
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}
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+static void gma_func0_disable(struct device *dev)
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+{
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+ /* Disable VGA decode */
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+ pci_or_config16(pcidev_on_root(0, 0), GGC, 1 << 1);
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+}
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+
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static struct device_operations gma_func0_ops = {
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.read_resources = pci_dev_read_resources,
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.set_resources = pci_dev_set_resources,
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.enable_resources = pci_dev_enable_resources,
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.init = gma_func0_init,
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.acpi_fill_ssdt = gma_generate_ssdt,
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+ .vga_disable = gma_func0_disable,
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.ops_pci = &pci_dev_ops_pci,
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};
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--
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2.39.2
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