commit 2dc15e9ea8522959e90def168e459e629ccec12f
author Nico Huber <nico.huber@secunet.com> Thu Feb 04 18:59:48 2016 +0100
committer Martin Roth <martinroth@google.com> Tue Feb 09 20:02:36 2016 +0100
tree 575cb8f40c3cc4464f02bdb83c9acee7f0dcbba4
parent b27c24f69b89aca3203d56522663a546811cbfb8

Revert "northbridge/intel/peg: Disable unused ports"

This reverts commit 0e06f5bd70b45fd330d8dfb1dc77cce043caf841.

It breaks gm45 and also does some magic without being asked too. It
disables bridge devices permanently if no device was found on the se-
condary bus. In a simple notebook world this might be ok, but it breaks
hot-plugging and late detection (if a secondary bus device comes up too
slow for the firmware to detect and the OS has to enumerate it).

Change-Id: Ia2010640d7c55b0bdd44164b81c75dd4be50410b
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/13609
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

src/northbridge/intel/sandybridge/northbridge.c

diff --git a/src/northbridge/intel/sandybridge/northbridge.c b/src/northbridge/intel/sandybridge/northbridge.c
index 3974fe8..53d93a2 100644
--- a/src/northbridge/intel/sandybridge/northbridge.c
+++ b/src/northbridge/intel/sandybridge/northbridge.c
@@ -368,17 +368,6 @@
 	DMIBAR32(0x88) = reg32;
 }
 
-static u8 scan_bus_unused(struct bus *link)
-{
-	struct device *dev;
-
-	for (dev = link->children; dev; dev = dev->sibling) {
-		if (dev->enabled)
-			return 0;
-	}
-	return 1;
-}
-
 /* Disable unused PEG devices based on devicetree */
 static void disable_peg(void)
 {
@@ -389,32 +378,27 @@
 	reg = pci_read_config32(dev, DEVEN);
 
 	dev = dev_find_slot(0, PCI_DEVFN(1, 2));
-	if (!dev || !dev->enabled ||
-			(dev->link_list && scan_bus_unused(dev->link_list))) {
+	if (!dev || !dev->enabled) {
 		printk(BIOS_DEBUG, "Disabling PEG12.\n");
 		reg &= ~DEVEN_PEG12;
 	}
 	dev = dev_find_slot(0, PCI_DEVFN(1, 1));
-	if (!dev || !dev->enabled ||
-			(dev->link_list && scan_bus_unused(dev->link_list))) {
+	if (!dev || !dev->enabled) {
 		printk(BIOS_DEBUG, "Disabling PEG11.\n");
 		reg &= ~DEVEN_PEG11;
 	}
 	dev = dev_find_slot(0, PCI_DEVFN(1, 0));
-	if (!dev || !dev->enabled ||
-			(dev->link_list && scan_bus_unused(dev->link_list))) {
+	if (!dev || !dev->enabled) {
 		printk(BIOS_DEBUG, "Disabling PEG10.\n");
 		reg &= ~DEVEN_PEG10;
 	}
 	dev = dev_find_slot(0, PCI_DEVFN(2, 0));
-	if (!dev || !dev->enabled ||
-			(dev->link_list && scan_bus_unused(dev->link_list))) {
+	if (!dev || !dev->enabled) {
 		printk(BIOS_DEBUG, "Disabling IGD.\n");
 		reg &= ~DEVEN_IGD;
 	}
 	dev = dev_find_slot(0, PCI_DEVFN(6, 0));
-	if (!dev || !dev->enabled ||
-			(dev->link_list && scan_bus_unused(dev->link_list))) {
+	if (!dev || !dev->enabled) {
 		printk(BIOS_DEBUG, "Disabling PEG60.\n");
 		reg &= ~DEVEN_PEG60;
 	}