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, 2 insertions, 10 deletions

diff --git a/sys/dev/fatm/if_fatm.c b/sys/dev/fatm/if_fatm.c
index 9020d22..abd8e79 100644
--- a/sys/dev/fatm/if_fatm.c
+++ b/sys/dev/fatm/if_fatm.c
@@ -2829,21 +2829,13 @@ fatm_attach(device_t dev)
 	ifp->if_linkmiblen = sizeof(IFP2IFATM(sc->ifp)->mib);
 
 	/*
-	 * Enable memory and bustmaster
+	 * Enable busmaster
 	 */
-	cfg = pci_read_config(dev, PCIR_COMMAND, 2);
-	cfg |= PCIM_CMD_MEMEN | PCIM_CMD_BUSMASTEREN;
-	pci_write_config(dev, PCIR_COMMAND, cfg, 2);
+	pci_enable_busmaster(dev);
 
 	/*
 	 * Map memory
 	 */
-	cfg = pci_read_config(dev, PCIR_COMMAND, 2);
-	if (!(cfg & PCIM_CMD_MEMEN)) {
-		if_printf(ifp, "failed to enable memory mapping\n");
-		error = ENXIO;
-		goto fail;
-	}
 	sc->memid = 0x10;
 	sc->memres = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->memid,
 	    RF_ACTIVE);