From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752015AbaFEO7g (ORCPT ); Thu, 5 Jun 2014 10:59:36 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:56735 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751314AbaFEO7e (ORCPT ); Thu, 5 Jun 2014 10:59:34 -0400 From: Daniel Vetter To: Intel Graphics Development Cc: DRI Development , LKML , Daniel Vetter , Greg Kroah-Hartman , Jiri Slaby Subject: [PATCH 2/5] vt: Fix up unregistration of vt drivers Date: Thu, 5 Jun 2014 16:58:25 +0200 Message-Id: <1401980308-5116-2-git-send-email-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1401980308-5116-1-git-send-email-daniel.vetter@ffwll.ch> References: <1401980308-5116-1-git-send-email-daniel.vetter@ffwll.ch> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A bunch of issues: - We should not kick out the default console (which is tracked in conswitchp), so check for that. - Add better error codes so callers can differentiate between "something went wrong" and "your driver isn't registered already". i915 needs that so it doesn't fall over when reloading the driver and hence vga_con is already unregistered. - There's a mess with the driver flags: What we need to check for is that the driver isn't used any more, i.e. unbound completely (FLAG_INIT). And not whether it's the boot console or not (which is the only one which doesn't have FLAG_MODULE). Otherwise there's no way to kick out the boot console, which i915 wants to do to prevent havoc with vga_con interferring (which tends to hang machines). Cc: Greg Kroah-Hartman Cc: Jiri Slaby Signed-off-by: Daniel Vetter --- drivers/tty/vt/vt.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index ea600f482eeb..5077fe87324d 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -3573,17 +3573,20 @@ err: */ int do_unregister_con_driver(const struct consw *csw) { - int i, retval = -ENODEV; + int i; /* cannot unregister a bound driver */ if (con_is_bound(csw)) - goto err; + return -EBUSY; + + if (csw == conswitchp) + return -EINVAL; for (i = 0; i < MAX_NR_CON_DRIVER; i++) { struct con_driver *con_driver = ®istered_con_driver[i]; if (con_driver->con == csw && - con_driver->flag & CON_DRIVER_FLAG_MODULE) { + con_driver->flag & CON_DRIVER_FLAG_INIT) { vtconsole_deinit_device(con_driver); device_destroy(vtconsole_class, MKDEV(0, con_driver->node)); @@ -3594,12 +3597,11 @@ int do_unregister_con_driver(const struct consw *csw) con_driver->flag = 0; con_driver->first = 0; con_driver->last = 0; - retval = 0; - break; + return 0; } } -err: - return retval; + + return -ENODEV; } EXPORT_SYMBOL_GPL(do_unregister_con_driver); -- 1.8.1.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: [PATCH 2/5] vt: Fix up unregistration of vt drivers Date: Thu, 5 Jun 2014 16:58:25 +0200 Message-ID: <1401980308-5116-2-git-send-email-daniel.vetter@ffwll.ch> References: <1401980308-5116-1-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1401980308-5116-1-git-send-email-daniel.vetter@ffwll.ch> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Intel Graphics Development Cc: Daniel Vetter , Jiri Slaby , LKML , DRI Development , Greg Kroah-Hartman List-Id: dri-devel@lists.freedesktop.org A bunch of issues: - We should not kick out the default console (which is tracked in conswitchp), so check for that. - Add better error codes so callers can differentiate between "something went wrong" and "your driver isn't registered already". i915 needs that so it doesn't fall over when reloading the driver and hence vga_con is already unregistered. - There's a mess with the driver flags: What we need to check for is that the driver isn't used any more, i.e. unbound completely (FLAG_INIT). And not whether it's the boot console or not (which is the only one which doesn't have FLAG_MODULE). Otherwise there's no way to kick out the boot console, which i915 wants to do to prevent havoc with vga_con interferring (which tends to hang machines). Cc: Greg Kroah-Hartman Cc: Jiri Slaby Signed-off-by: Daniel Vetter --- drivers/tty/vt/vt.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index ea600f482eeb..5077fe87324d 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -3573,17 +3573,20 @@ err: */ int do_unregister_con_driver(const struct consw *csw) { - int i, retval = -ENODEV; + int i; /* cannot unregister a bound driver */ if (con_is_bound(csw)) - goto err; + return -EBUSY; + + if (csw == conswitchp) + return -EINVAL; for (i = 0; i < MAX_NR_CON_DRIVER; i++) { struct con_driver *con_driver = ®istered_con_driver[i]; if (con_driver->con == csw && - con_driver->flag & CON_DRIVER_FLAG_MODULE) { + con_driver->flag & CON_DRIVER_FLAG_INIT) { vtconsole_deinit_device(con_driver); device_destroy(vtconsole_class, MKDEV(0, con_driver->node)); @@ -3594,12 +3597,11 @@ int do_unregister_con_driver(const struct consw *csw) con_driver->flag = 0; con_driver->first = 0; con_driver->last = 0; - retval = 0; - break; + return 0; } } -err: - return retval; + + return -ENODEV; } EXPORT_SYMBOL_GPL(do_unregister_con_driver); -- 1.8.1.4