Update PCI drivers to no longer look at the MEMIO-enabled bit in the PCI

command register.  The lazy BAR allocation code in FreeBSD sometimes
disables this bit when it detects a range conflict, and will re-enable
it on demand when a driver allocates the BAR.  Thus, the bit is no longer
a reliable indication of capability, and should not be checked.  This
results in the elimination of a lot of code from drivers, and also gives
the opportunity to simplify a lot of drivers to use a helper API to set
the busmaster enable bit.

This changes fixes some recent reports of disk controllers and their
associated drives/enclosures disappearing during boot.

Submitted by:	jhb
Reviewed by:	jfv, marius, achadd, achim
MFC after:	1 day

1 files changed, 1 insertions, 9 deletions

diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index b3327e8..16e1d6f 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -2442,16 +2442,8 @@ em_identify_hardware(struct adapter *adapter)
 	device_t dev = adapter->dev;
 
 	/* Make sure our PCI config space has the necessary stuff set */
+	pci_enable_busmaster(dev);
 	adapter->hw.bus.pci_cmd_word = pci_read_config(dev, PCIR_COMMAND, 2);
-	if (!((adapter->hw.bus.pci_cmd_word & PCIM_CMD_BUSMASTEREN) &&
-	    (adapter->hw.bus.pci_cmd_word & PCIM_CMD_MEMEN))) {
-		device_printf(dev, "Memory Access and/or Bus Master bits "
-		    "were not set!\n");
-		adapter->hw.bus.pci_cmd_word |=
-		(PCIM_CMD_BUSMASTEREN | PCIM_CMD_MEMEN);
-		pci_write_config(dev, PCIR_COMMAND,
-		    adapter->hw.bus.pci_cmd_word, 2);
-	}
 
 	/* Save off the information about this board */
 	adapter->hw.vendor_id = pci_get_vendor(dev);