Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752501AbaFFHQQ (ORCPT ); Fri, 6 Jun 2014 03:16:16 -0400 Received: from mail-ig0-f171.google.com ([209.85.213.171]:34957 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751802AbaFFHQO (ORCPT ); Fri, 6 Jun 2014 03:16:14 -0400 MIME-Version: 1.0 In-Reply-To: <1401980308-5116-1-git-send-email-daniel.vetter@ffwll.ch> References: <1401980308-5116-1-git-send-email-daniel.vetter@ffwll.ch> Date: Fri, 6 Jun 2014 09:16:13 +0200 Message-ID: Subject: Re: [PATCH 1/5] vt: Fix replacement console check when unbinding From: David Herrmann To: Daniel Vetter Cc: Intel Graphics Development , Jiri Slaby , LKML , DRI Development , Greg Kroah-Hartman Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi On Thu, Jun 5, 2014 at 4:58 PM, Daniel Vetter wrote: > I don't fully understand the magic of the vt register/unregister > logic, but apparently everything but the inital console (as set > in the conswitchp pointer) is marked with FLAG_MODULE. Which means > if something unregistered the boot vt driver (e.g. i915.ko kicking > out vga_con) there's nothing left when trying to unbind e.g. fbcon > through sysfs. > > But we always have the dummy console hanging around, so this test > is fairly dubious. What we actually want is simply a different console > than the one we want to unbind. For unknown reasons, you can disable the dummy console via Kconfig, so it's not guaranteed to be around. But your comment is still valid. > > Cc: Greg Kroah-Hartman > Cc: Jiri Slaby > Signed-off-by: Daniel Vetter > --- > drivers/tty/vt/vt.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c > index 3ad0b61e35b4..ea600f482eeb 100644 > --- a/drivers/tty/vt/vt.c > +++ b/drivers/tty/vt/vt.c > @@ -3155,8 +3155,7 @@ int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt > for (i = 0; i < MAX_NR_CON_DRIVER; i++) { > con_back = ®istered_con_driver[i]; > > - if (con_back->con && > - !(con_back->flag & CON_DRIVER_FLAG_MODULE)) { > + if (con_back->con && con_back->con != csw) { Funny thing is, if you run do_bind_con_driver() on the range first, you kick out the existing driver and can then unload it regardless whether the fallback was FLAG_MODULE or not. Therefore, I think that change is safe. This is: Reviewed-by: David Herrmann Thanks David > defcsw = con_back->con; > retval = 0; > break; > -- > 1.8.1.4 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/