If get_pbus() is called for a device which has no parent/ancestor bus

with nonzero PCI bus operations, get_pbus() will get stuck in a silent
endless loop.
Detect the endless loop and break out with an error message.

Such a situation can happen if the device tree is not yet
initialized/walked completely.

This fixes the unexplainable hang if pci_{read,write}_config{8,16,32}was
used in early mainboard code for the AMD DBM690T. Instead, the code will
now die() with a meaningful error message.

Thanks to Ward Vandewege for testing my patches to track down that bug.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Marc Jones <marcj303@gmail.com>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3972 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Carl-Daniel Hailfinger 2009-03-05 19:33:12 +00:00
parent ac12ecd27a
commit bba113ec07
1 changed files with 6 additions and 0 deletions

View File

@ -28,6 +28,12 @@ static struct bus *get_pbus(device_t dev)
{
struct bus *pbus = dev->bus;
while(pbus && pbus->dev && !ops_pci_bus(pbus)) {
if (pbus == pbus->dev->bus) {
printk_alert("%s in endless loop looking for a parent "
"bus with ops_pci_bus for %s, breaking out\n",
__func__, dev_path(dev));
break;
}
pbus = pbus->dev->bus;
}
if (!pbus || !pbus->dev || !pbus->dev->ops || !pbus->dev->ops->ops_pci_bus) {