Description of problem: I tried to install the x86_64 RHEL-4 U6 installer kernel on my test machine, which has a DG965RY chipset - this has Intel's onboard 3D graphics controller. The boot locks solidly during the probing of the PCI hardware as far as I can tell: ... PCI: Using configuration type 1 PCI: Using MMCONFIG at f0000000 mtrr: v2.0 (20020519) ACPI: Subsystem revision 20040816 ACPI: Interpreter enabled ACPI: Using IOAPIC for interrupt routing ACPI: PCI Root Bridge [PCI0] (00:00) PCI: Probing PCI hardware (bus 00) At this point, the computer must be given a hard reset. I've tried various other RHEL-4 installer kernels too, including gold, and both AS and Desktop, but to no avail. All fail in the same manner. RHEL-5 kernels, various Fedora kernels, and all the 2.6 kernels I've built for it since Sept 2006 work. Also, i386 kernels show the same malfunction. The same kernels do, however, boot on my desktop box, which has a DP965LT of similar age. This lacks the on-board graphics. My test box has no PCI devices plugged into the expansion bus.
I put some printks into the PCI probing code, and have determined that the box locks up when pci_read_bases() attempts to determine the size of PCI_BASE_ADDRESS_2 with this line: reg = PCI_BASE_ADDRESS_0 + (pos << 2); pci_read_config_dword(dev, reg, &l); pci_write_config_dword(dev, reg, ~0); <<<<<<<<<< here pci_read_config_dword(dev, reg, &sz); pci_write_config_dword(dev, reg, l);
Adding "pci=nommconf" to the command line fixes the problem.
Created attachment 297689 [details] Disable PCI IO & MEM access on a device we're probing for BAR size The G965 graphics hardware BARs can be probed, provided that access through the I/O and Memory regions on that device are disabled for the duration of the probe. I'm told by an Intel engineer that PCI_COMMAND_{IO,MEMORY} should always be disabled during BAR probing.
*** This bug has been marked as a duplicate of 250313 ***