x86/iosf: Add Kconfig prompt for IOSF_MBI selection

commit aa8e4f22ab7773352ba3895597189b8097f2c307 upstream.

Fixes an error in having the iosf build as 'default m'. On X86 SoC's the iosf
sideband is the only way to access information for some registers, as opposed to
through MSR's on other Intel architectures. While selecting IOSF_MBI is
preferred, it does mean carrying extra code on non-SoC architectures. This
exports the selection to the user, allowing those driver writers to compile out
iosf code if it's not being built.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1409175640-32426-2-git-send-email-david.e.box@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: William Dauchy <william@gandi.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5dab54accc567ddb6237c6f670329b068d800b43..96e743ac28f3245ea19ea02342f3d9f33c4772a8 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2440,9 +2440,19 @@ config X86_DMA_REMAP
        depends on STA2X11
 
 config IOSF_MBI
-       tristate
-       default m
+       tristate "Intel System On Chip IOSF Sideband support"
        depends on PCI
+       ---help---
+         Enables sideband access to mailbox registers on SoC's. The sideband is
+         available on the following platforms. This list is not meant to be
+         exclusive.
+          - BayTrail
+          - Cherryview
+          - Braswell
+          - Quark
+
+         You should say Y if you are running a kernel on one of these
+         platforms.
 
 source "net/Kconfig"