ahci: Don't fail attach if the MSI-X BARs cannot be allocated

[jhb]

Summary

If the MSI-X table and/or PBA live in separate BAR(s) and those BAR(s)
cannot be allocated, fall back to using MSI or INTx instead of failing
attach.

PR: 289748
Reported by: Vitalij Satanivskij <[e-mail]>

[avg]

sys/dev/ahci/ahci_pci.c

595

If we got here then we successfully allocated r_msix_table.
Then it probably would be a good idea to release it?

[jhb]

sys/dev/ahci/ahci_pci.c

595

Maybe, but it doesn't hurt to keep it mapped (and the PCI bus won't actually unmap the BAR if we do anyway). That seems like a very rare case that isn't worth the complexity. When the device detaches, ahci_free_mem() will release the resource.

Note though that there is a bug in ahci_pci_detach(), it needs to call pci_release_msi() before it frees the BARs.