openwrt/target/linux/bcm47xx/patches-5.15/900-ssb-reject-PCI-writes-setting-CardBus-bridge-resourc.patch

From 5c81397a0147ea59c778d1de14ef54e2268221f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Wed, 8 Apr 2015 06:58:11 +0200
Subject: [PATCH] ssb: reject PCI writes setting CardBus bridge resources
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If SoC has a CardBus we can set resources of device at slot 1 only. It's
impossigle to set bridge resources as it simply overwrites device 1
configuration and usually results in Data bus error-s.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
 drivers/ssb/driver_pcicore.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/ssb/driver_pcicore.c
+++ b/drivers/ssb/driver_pcicore.c
@@ -165,6 +165,10 @@ static int ssb_extpci_write_config(struc
 	WARN_ON(!pc->hostmode);
 	if (unlikely(len != 1 && len != 2 && len != 4))
 		goto out;
+	/* CardBus SoCs allow configuring dev 1 resources only */
+	if (extpci_core->cardbusmode && dev != 1 &&
+	    off >= PCI_BASE_ADDRESS_0 && off <= PCI_BASE_ADDRESS_5)
+		goto out;
 	addr = get_cfgspace_addr(pc, bus, dev, func, off);
 	if (unlikely(!addr))
 		goto out;