|Summary:||[em] em driver doesn't use MSI on MSI capable device|
|Product:||Base System||Reporter:||Arthur Hartwig <arthur.hartwig>|
|Severity:||Affects Only Me||CC:||sbruno|
Description Arthur Hartwig 2007-05-16 08:30:04 UTC
FreeBSD 7 built a few weeks ago used MSI on two MSI capable interfaces (82572 chips). The recent substantial changes to emdriver have broken emdriver's use of MSI. Inspection of if_em.c shows em_attach() calls em_allocate_pci_resources() which for a 82572 based NIC to use MSI ends up requiring the bus.type field in the adapter structure to be set to e1000_bus_type_pci_express. However the bus type is not initialised until the call to e1000_get_bus_info() which is called AFTER em_attach() calls em_allocate_pci_resources(). I have been investigating the use of MSI to avoid interrupt sharing in a new system with a significant number of PCI express NICs.
Comment 1 Remko Lodder 2007-05-16 15:19:27 UTC
Responsible Changed From-To: freebsd-bugs->jfv Over to maintainer.
Comment 2 Sean Bruno 2015-06-29 17:51:06 UTC
There has been significant changes to the em(4) driver since this bug was reported. If MSI handling is still broken for these cards on the 10.2r release, please open a new ticket.