[SRU][N][PATCH 1/1] UBUNTU: SAUCE: iommu/intel: disable DMAR for CFL and WHL integrated gfx

[AceLan Kao]

From: "Chia-Lin Kao (AceLan)" <acelan.kao at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/2136958

This patch addresses screen flickering issues on systems with CoffeeLake
and WhiskeyLake integrated graphics, identified under Ubuntu kernel version
6.8.0-x. Similar to the issues seen with Skylake, KabyLake, and CometLake,
the flickering is caused by changes to the Ubuntu kernel configuration,
specifically the enabling of CONFIG_INTEL_IOMMU_DEFAULT_ON and
CONFIG_INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON.

The problem persists in the latest drm tip
(6.19.0-061900rc4drmtip20260107-generic), and there is an upstream bug
addressing the issue.
https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11504

Before there is a real fix for the issue, we add the affected GPU IDs
to the quirk to disable their DMAR.

Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao at canonical.com>
---
 drivers/iommu/intel/iommu.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 3043eceebbc9d..9873e0567e941 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5115,6 +5115,31 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9B41, quirk_iommu_igfx);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9BCA, quirk_iommu_igfx);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9BCC, quirk_iommu_igfx);

+/* CFL */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E90, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E91, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E92, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E93, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E94, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E96, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E98, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E99, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E9A, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E9B, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3E9C, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA5, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA6, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA7, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA8, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA9, quirk_iommu_igfx);
+
+/* WHL */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA0, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA1, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA2, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA3, quirk_iommu_igfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3EA4, quirk_iommu_igfx);
+
 /* disable IPU dmar support */
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, quirk_iommu_ipu);

--
2.51.0