[3.16.y-ckt stable] Patch "xen kconfig: don't "select INPUT_XEN_KBDDEV_FRONTEND"" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    xen kconfig: don't "select INPUT_XEN_KBDDEV_FRONTEND"

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt27.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 1d2930502e44eab3708126fbbb576a42976d15cb Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd at arndb.de>
Date: Tue, 16 Feb 2016 16:03:23 +0100
Subject: xen kconfig: don't "select INPUT_XEN_KBDDEV_FRONTEND"

commit 13aa38e291bdd4e4018f40dd2f75e464814dcbf3 upstream.

The Xen framebuffer driver selects the xen keyboard driver, so the latter
will be built-in if XEN_FBDEV_FRONTEND=y. However, when CONFIG_INPUT
is a loadable module, this configuration cannot work. On mainline kernels,
the symbol will be enabled but not used, while in combination with
a patch I have to detect such useless configurations, we get the
expected link failure:

drivers/input/built-in.o: In function `xenkbd_remove':
xen-kbdfront.c:(.text+0x2f0): undefined reference to `input_unregister_device'
xen-kbdfront.c:(.text+0x30e): undefined reference to `input_unregister_device'

This removes the extra "select", as it just causes more trouble than
it helps. In theory, some defconfig file might break if it has
XEN_FBDEV_FRONTEND in it but not INPUT_XEN_KBDDEV_FRONTEND. The Kconfig
fragment we ship in the kernel (kernel/configs/xen.config) however
already enables both, and anyone using an old .config file would
keep having both enabled.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Suggested-by: David Vrabel <david.vrabel at citrix.com>
Fixes: 36c1132e34bd ("xen kconfig: fix select INPUT_XEN_KBDDEV_FRONTEND")
Acked-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/video/fbdev/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 59c98bfd5a8a..fac73ceb90e5 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -2243,7 +2243,6 @@ config XEN_FBDEV_FRONTEND
 	select FB_SYS_IMAGEBLIT
 	select FB_SYS_FOPS
 	select FB_DEFERRED_IO
-	select INPUT_XEN_KBDDEV_FRONTEND if INPUT_MISC
 	select XEN_XENBUS_FRONTEND
 	default y
 	help