The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1c1a3b4d3e86b997a313ffb297c1129540882859 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@xxxxxxxxxx> Date: Wed, 24 Nov 2021 16:59:39 +0100 Subject: [PATCH] PCI: pci-bridge-emul: Make expansion ROM Base Address register read-only MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If expansion ROM is unsupported (which is the case of pci-bridge-emul.c driver) then ROM Base Address register must be implemented as read-only register that return 0 when read, same as for unused Base Address registers. Link: https://lore.kernel.org/r/20211124155944.1290-2-pali@xxxxxxxxxx Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic") Signed-off-by: Pali Rohár <pali@xxxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c index db97cddfc85e..5de8b8dde209 100644 --- a/drivers/pci/pci-bridge-emul.c +++ b/drivers/pci/pci-bridge-emul.c @@ -139,8 +139,13 @@ struct pci_bridge_reg_behavior pci_regs_behavior[PCI_STD_HEADER_SIZEOF / 4] = { .ro = GENMASK(7, 0), }, + /* + * If expansion ROM is unsupported then ROM Base Address register must + * be implemented as read-only register that return 0 when read, same + * as for unused Base Address registers. + */ [PCI_ROM_ADDRESS1 / 4] = { - .rw = GENMASK(31, 11) | BIT(0), + .ro = ~0, }, /*
