On Aug 17, 2011, at 12:11 PM, David Young wrote: > On Wed, Aug 17, 2011 at 11:52:18AM -0700, Matt Thomas wrote: >> On Aug 17, 2011, at 9:35 AM, David Young wrote: >>>> int pci_msi_type(pci_chipset_tag_t pc, pci_msi_handle_t msih); >>>> >>>> return the type of msi allocated (PCI_CAP_MSI or PCI_CAP_MSIX). In the >>>> latter case MSI vectors may not be contiguous. >>> >>> Does it matter to the driver whether or not the vectors are contiguous? >>> Presumably there are no gaps in the available msirq? >> >> MSIX doesn't matter, MSI it does. > > Can you give an example where a user of this API has to care whether the > vectors are contiguous or not?
MSI requires contiguous vectors. Period. MSIX doesn't since each vector has a separate MSIX table entry. >>>> void pci_msi_disestablish(pci_chipset_tag_t pc, void *ih); >>>> >>>> Disestablishes but does not free the MSI. >>> >>> You mean, pci_msi_disestablish() does not free to the MSI handle's pool? >>> Why not? >> >> It does. But not to the system pool. pci_msi_free does that. > > Does pci_msi_free() give back "excess" msirqs to the system pool? Can > you give an example of how/why it is used? It gives all back. You can't release a portion, it's all or nothing.
