FAILED: patch "[PATCH] PCI: pci-bridge-emul: Make expansion ROM Base Address" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

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@vger.kernel.org>.

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@kernel.org>
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@kernel.org
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

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,
 	},
 
 	/*