From patchwork Mon Feb 15 16:51:08 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 8316811 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6AF07C02AA for ; Mon, 15 Feb 2016 17:01:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8F290203A9 for ; Mon, 15 Feb 2016 17:01:42 +0000 (UTC) Received: from bombadil.infradead.org (unknown [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 718DC202AE for ; Mon, 15 Feb 2016 17:01:41 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aVMNX-0003Ak-Ly; Mon, 15 Feb 2016 16:52:03 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aVMNS-00032J-Ke for linux-arm-kernel@lists.infradead.org; Mon, 15 Feb 2016 16:52:00 +0000 X-IronPort-AV: E=Sophos;i="5.22,451,1449532800"; d="scan'208";a="331758851" Date: Mon, 15 Feb 2016 16:51:08 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Arnd Bergmann Subject: Re: [PATCH] xen kconfig: clarify INPUT_XEN_KBDDEV_FRONTEND select In-Reply-To: <1455278707-2008263-1-git-send-email-arnd@arndb.de> Message-ID: References: <1455278707-2008263-1-git-send-email-arnd@arndb.de> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 X-DLP: MIA1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160215_085159_038429_077CC950 X-CRM114-Status: GOOD ( 18.24 ) X-Spam-Score: -6.9 (------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Jones , xen-devel@lists.xensource.com, Konrad Rzeszutek Wilk , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Tomi Valkeinen , David Vrabel , boris.ostrovsky@oracle.com, Jean-Christophe Plagniol-Villard , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-3.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RDNS_NONE,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP CC'ing a few others. On Fri, 12 Feb 2016, 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 This looks very hackish. Couldn't we just do the following? diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index 8ea45a5..3c15f6d 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -2246,7 +2246,7 @@ 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 INPUT_XEN_KBDDEV_FRONTEND if (INPUT && INPUT_MISC) select XEN_XENBUS_FRONTEND default y help