[net] Gracefully handle shared e1000/1000e driver PCI ID's

Both the old e1000 driver and the new e1000e driver can drive some
PCI-Express e1000 cards, and we should avoid ambiguity about which
driver will pick up the support for those cards when both drivers are
enabled.

This solves the problem by having the old driver support those cards if
the new driver isn't configured, but otherwise ceding support for PCI
Express versions of the e1000 chipset to the newer driver.  Thus
allowing both legacy configurations where only the old driver is active
(and handles all chips it knows about) and the new configuration with
the new driver handling the more modern PCIE variants.

Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 5a2d1dd..6c57540 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -1992,7 +1992,7 @@
 
 config E1000E
 	tristate "Intel(R) PRO/1000 PCI-Express Gigabit Ethernet support"
-	depends on PCI && EXPERIMENTAL
+	depends on PCI
 	---help---
 	  This driver supports the PCI-Express Intel(R) PRO/1000 gigabit
 	  ethernet family of adapters. For PCI or PCI-X e1000 adapters,
@@ -2009,6 +2009,9 @@
 	  To compile this driver as a module, choose M here. The module
 	  will be called e1000e.
 
+config E1000E_ENABLED
+	def_bool E1000E != n
+
 config IP1000
 	tristate "IP1000 Gigabit Ethernet support"
 	depends on PCI && EXPERIMENTAL