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authorNaval Alcalá <ari@naval.cat>2026-05-09 05:43:44 +0300
committerJoerg Roedel <joerg.roedel@amd.com>2026-05-11 11:19:36 +0300
commit2cda2e10dc8343ae01eae9e999a876b7e7d37861 (patch)
treea4ef0a671a6b76aceb8be51cea9150c66852058c
parent15dd29ca620648a18a0334a3f6b26af181154a23 (diff)
downloadlinux-2cda2e10dc8343ae01eae9e999a876b7e7d37861.tar.xz
iommu/vt-d: Disable DMAR for Intel Q35 IGFX
Intel Q35 integrated graphics (8086:29b2) exhibits broken DMAR behaviour similar to other G4x/GM45 devices for which DMAR is already disabled via quirks. When DMAR is enabled, the system may hard lock up during boot or early device initialization, requiring a reset. Add the missing PCI ID to the existing quirk list to disable DMAR for this device. Fixes: 1f76249cc3be ("iommu/vt-d: Declare Broadwell igfx dmar support snafu") Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=201185 Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216064 Signed-off-by: Naval Alcalá <ari@naval.cat> Link: https://lore.kernel.org/r/20260410161622.13549-1-ari@naval.cat Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
-rw-r--r--drivers/iommu/intel/iommu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index c3d18cd77d2f..2a6b6813a78d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3937,6 +3937,9 @@ static void quirk_iommu_igfx(struct pci_dev *dev)
disable_igfx_iommu = 1;
}
+/* Q35 integrated gfx dmar support is totally busted. */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x29b2, quirk_iommu_igfx);
+
/* G4x/GM45 integrated gfx dmar support is totally busted. */
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_igfx);