From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Date: Fri, 12 Feb 2016 13:56:45 +0000 Subject: Re: [PATCH] xen kconfig: clarify INPUT_XEN_KBDDEV_FRONTEND select Message-Id: <20160212135645.ouppx4ijselfomjy@hawk.localdomain> List-Id: References: <1455278707-2008263-1-git-send-email-arnd@arndb.de> In-Reply-To: <1455278707-2008263-1-git-send-email-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Fri, Feb 12, 2016 at 01:04:40PM +0100, Arnd Bergmann wrote: > 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 changes the dependencies of XEN_FBDEV_FRONTEND so it cannot be > built-in if CONFIG_INPUT=m && CONFIG_INPUT_MISC=y, as that would result > in the broken select. > > As usual, we would be much better off without the 'select', but removing > it now would likely break existing user configurations that depend on > it, so this adds another hack on top to get it working. > > Signed-off-by: Arnd Bergmann > Fixes: 36c1132e34bd ("xen kconfig: fix select INPUT_XEN_KBDDEV_FRONTEND") > --- > drivers/video/fbdev/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig > index 8ea45a5cd806..fd3d6fd290a9 100644 > --- a/drivers/video/fbdev/Kconfig > +++ b/drivers/video/fbdev/Kconfig > @@ -2241,6 +2241,7 @@ config FB_VIRTUAL > config XEN_FBDEV_FRONTEND > tristate "Xen virtual frame buffer support" > depends on FB && XEN > + depends on INPUT || !INPUT_MISC > select FB_SYS_FILLRECT > select FB_SYS_COPYAREA > select FB_SYS_IMAGEBLIT > -- > 2.7.0 > Reviewed-by: Andrew Jones Thanks, drew