>>> On 04.10.13 at 19:29, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > On Wed, Oct 02, 2013 at 04:43:46PM -0400, Aaron Opfer wrote: >> First time submitting the kernel dev list, so if I have demonstrated >> gross incompetence in some way, please cut me some slack. :) >> >> I discussed with Clemens Ladisch an issue I was having that I thought >> was related to the driver he authored for my soundcard, but on his >> suggestion I experimented with other PCI devices and we have narrowed >> the issue to the PCI Bridge. >> >> What hints me toward DMA handling being the fault is the following >> message I receive during kernel initialization after rebooting from an >> Xen hypervisor into a baremetal-kernel, without a power-cycle: >> >> [0.012815] dmar: DRHD: handling fault status reg 3 >> [0.012868] dmar: DMAR:[DMA Read] Request device [07:00.0] fault addr 7e00000 >> [0.012868] DMAR:[fault reason 02] Present bit in context entry is clear That's a firmware or native Linux problem then - even during a "warm" boot all settings a prior OS may have effected to the hardware must be erased by the firmware (i.e. all components have to undergo a sufficient level of resetting) for the new OS to be permitted to make assumptions of the system coming up in a reasonably consistent state. IOW either some assumption made by native Linux is invalid, or the firmware doesn't make sure a valid assumption actually holds. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
