On Thursday 14 January 2010 12:46:22 am Yinghai Lu wrote: > On 01/13/2010 05:24 AM, Jeff Garrett wrote: > > On Wed, Jan 13, 2010 at 12:45:17AM -0800, Yinghai Lu wrote: > >> On Wed, Jan 13, 2010 at 12:44 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > >>> On Tue, Jan 12, 2010 at 9:37 PM, Jeff Garrett <jeff@xxxxxxxxxxxx> wrote: > >>>> Took a stab at getting the right emails. If I missed anyone, sorry... > >>>> > >>>> I have a desktop machine with a radeon HD 4850, and on recent kernels > >>>> the radeon driver has failed with the message "No valid linear > >>>> framebuffer address". lspci on the broken configuration showed the > >>>> first memory region at d0000000 of the radeon card to be ignored. dmesg > >>>> showed there to be a host bridge window at that address which was also > >>>> ignored. > >>> it seems HW IOH only can use [e000000 - fdffffff] under that bridge... > >>> > >>> and _CRS said the peer root bus could use [c000000 - dfffffff] > >>> > >>> could be that we need to check other register to decide if we can use > >>> reading from ioh reg directly. > not sure why [0xc000000 - 0xcffffff] should work with 00:07.0 > > checked with intel doc, that is out of scope to LMMIOL register... > > really don't know how it works with your platform. I wonder about that [mem 0xc0000000-0xcfffffff] range, too. But as far as I can tell, we don't actually try to use that anywhere yet. (We assign part of that range to the 00:1c.0 bridge to bus 03, but I don't see any devices actually using it.) One problem I see is that _CRS includes the [mem 0xd0000000-0xdfffffff] range, but intel_bus.c didn't find it. We DO need this range for the Radeon, and the Radeon works with "pci=use_crs", so the host bridge must be routing it. I think this must be a detail of the Intel host bridge, not something specific to Jeff's Dell system. This problem should affect all systems using that host bridge. PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0xe0000000-0xefffffff] (base 0xe0000000) ACPI: PCI Root Bridge [PCI0] (0000:00) pci_root PNP0A08:00: host bridge window [mem 0xc0000000-0xdfffffff] pci_root PNP0A08:00: host bridge window [mem 0xf0000000-0xfed8ffff] IOH bus: [00, fb] IOH bus: 00 index 1 mmio: [e0000000, fdffffff] pci 0000:00:07.0: PCI bridge to [bus 04-04] pci 0000:00:07.0: bridge window [mem 0xd0000000-0xdfffffff 64bit pref] pci 0000:04:00.0: reg 10: [mem 0xd0000000-0xdfffffff 64bit pref] Another problem is that intel_bus.c didn't remove the MMCONFIG region [mem 0xe0000000-0xefffffff] from the window. I think there's code there to do that, but there must be something wrong with it. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
