Patrick Georgi (pgeorgi@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8734
-gerrit
commit 8d9b6e94f8b0574cb8b5683dbd9986d4c4bf6913 Author: Lee Leahy leroy.p.leahy@intel.com Date: Wed Dec 17 13:05:26 2014 -0800
libpayload: PCI bus scan - Eliminate endless loop
Don't attempt to scan the PCI bus if the bridge is disabled. When the PCI bridge is not setup and enabled, it is possible for the secondary bus register to contain the value zero (0). In this case the usb_scan_pci_bus routine gets into an infinite recursive loop which ends only when the heap or stack is exhausted. This patch verifies that the PCI bridge is enabled by verifying that it is enabled for either memory or I/O operations. When enabled, the secondary bus is scanned.
BRANCH=none BUG=None TEST=Build and run on Samus
Change-Id: I6826dc1d73b7c24729de5ac7c4d3534922ca73c5 Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: 63d04b47934761351b54c847a2692bdef81ce54f Original-Change-Id: I855240c52fa3eba841e6754816ebbcb824abc4cd Original-Signed-off-by: Lee Leahy Leroy.P.Leahy@intel.com Original-Reviewed-on: https://chromium-review.googlesource.com/236382 Original-Commit-Queue: Leroy P Leahy leroy.p.leahy@intel.com Original-Tested-by: Leroy P Leahy leroy.p.leahy@intel.com Original-Reviewed-by: Giri P Mudusuru giri.p.mudusuru@intel.com Original-Reviewed-by: Duncan Laurie dlaurie@chromium.org --- payloads/libpayload/drivers/usb/usbinit.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/payloads/libpayload/drivers/usb/usbinit.c b/payloads/libpayload/drivers/usb/usbinit.c index 6fb7d4b..4225c3f 100644 --- a/payloads/libpayload/drivers/usb/usbinit.c +++ b/payloads/libpayload/drivers/usb/usbinit.c @@ -146,9 +146,13 @@ static void usb_scan_pci_bus(int bus) header_type = pci_read_config8(pci_device, REG_HEADER_TYPE); /* If this is a bridge, scan the other side. */ if ((header_type & ~HEADER_TYPE_MULTIFUNCTION) == - HEADER_TYPE_BRIDGE) - usb_scan_pci_bus(pci_read_config8(pci_device, - REG_SECONDARY_BUS)); + HEADER_TYPE_BRIDGE) { + /* Verify that the bridge is enabled */ + if ((pci_read_config16(pci_device, REG_COMMAND) + & 3) != 0) + usb_scan_pci_bus(pci_read_config8( + pci_device, REG_SECONDARY_BUS)); + } else usb_controller_initialize(bus, dev, func); }