From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934677AbdAKVme convert rfc822-to-8bit (ORCPT ); Wed, 11 Jan 2017 16:42:34 -0500 Received: from mout.gmx.net ([212.227.17.22]:62475 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934544AbdAKVmb (ORCPT ); Wed, 11 Jan 2017 16:42:31 -0500 Message-ID: <1484170890.1301.8.camel@gmx.de> Subject: Re: [PATCH v9 4/4] console: Make persistent scrollback a boot parameter From: Manuel =?ISO-8859-1?Q?Sch=F6lling?= To: Adam Borowski Cc: gregkh@linuxfoundation.org, jslaby@suse.com, lkml14@scotdoyle.com, rdunlap@infradead.org, shorne@gmail.com, andrey_utkin@fastmail.com, akpm@linux-foundation.org, paul.burton@imgtec.com, daniel.vetter@ffwll.ch, tj@kernel.org, hdegoede@redhat.com, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org Date: Wed, 11 Jan 2017 22:41:30 +0100 In-Reply-To: <20170110225846.gd2pqczplnkl74d3@angband.pl> References: <4640722.jsFVORW8WM@amdc3058> <20170110212838.16175-5-manuel.schoelling@gmx.de> <20170110225846.gd2pqczplnkl74d3@angband.pl> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K0:uR9pxojpb5+r74hHigytWqvSNSuL0GWiOC+EDA69Ooc8E+mzzyt wxiQk4GejHezye12h6M72d+b7ir7JQt2bhJKOw9J2L13xGASFNbVqxS9hniUZngXZMMp+sw R81HxP//SWdLnx/Wh3w87Z3FogkYn1OaicSpDJ1omO1aDpoUxx1+TZqclWMu0y+HLxvnSCd 2zCVlknE4Qj7B1S51UQBg== X-UI-Out-Filterresults: notjunk:1;V01:K0:AfEtEcArkLU=:n3jY47h2RSUf5J6n+0/M4i a3atCO6ro7D6aZHPXoThj3nDytw6TrvecUkOQxei2n74Tvx/9DA+PcwYrzai+m9AnC6sd/77G 88hzllulaDXuZf3/RbrtA+LOYvRiwefNxbXYlZ2LPoyZLkdw3nFF1en7ME9f8VgRAVDwOtQpq iXCSPiBnJ80abE0peR5jOSJ5/J/i/s2AGKXsWrF+1msa3HqI/HlrPqAllZCk6wdVMSszYXZOw vcKTWnE7bqMrxuq7Uq2gbtHsGntPvsADU9Z1TghKz3KacOvs+nztqBs2viW9bslJg282oWwFc 8RX+Kqsk2dHD67Hr96ZKisVlA6RHzTlIFnB5jIPhBOlNikTVvQW8ppKC75jOWjnpst9M30/VR AZ5Vwop2aPp2ov+jiYdy+0JDPr0e/y77zYICESUjsuoT6zpPU3oqRZr2rhk3RgU74UhecRlH2 cI0Fecyq5hNIwSAJYgk5jkXr1bEvULdHXZD+cPoQeCKNKTui0BgVbX2aoIDHLpm1uKjoEVJRu LJAw9SUQU+rde0D80J+FrX0TWbvS4urTJU+98v0zJlHvUqc8CrgewGK9fE2V/dqsAWjIeL7wg XsQRBCJWxyrFNH99RG8niEpx2XJ3Q70g+QxmZB/1NPL3KhFOaUPbvMHHMHcrRBrq+RJoPNKWA FUEzEtPyqws7TkP4XqMkYIUQ5d5uvEj+Y0HYz2noJeWaZ9UpNBdbt6DCl+eGgrGRkRW3z+LjY uG7XdUyHQL744p+iCVuh0OUa7ri0EWbVm4UEtZVPAHLfZZXZcq2dskCSSuRG9tFYrsISG2FBf RmKksR7DknJGnJGNJFJz07Cc/jqtVMFvDhtICiHTVtSWXvCfn96u7YxIBNIMT2W1ps41LfMvB LcaDGcJBMVbWVEkZnwO0P/pPXINXx9Ed9jW4aT0VIo5Epcqkx1sZboAYbtlMu2I2nLQRKhDNC +KBuKcdF0p1+3o0LdC0aEaQ5FX5U+mukT6L3f1cvFLwZgQ73B3OhAxM5oiDkJ4KlUf/LrsEQ2 qhc9RWMLQN1qMbm30A1VuqTntcrqAwfsorbkJvy3wYDhLCfg7NtPIfKnjLgL5Hh+pw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2017-01-10 at 23:58 +0100, Adam Borowski wrote: > On Tue, Jan 10, 2017 at 10:28:38PM +0100, Manuel Schölling wrote: > > The impact of the persistent scrollback feature on the code size is > > rather small, so the config option is removed. The feature stays > > disabled by default and can be enabled by using the boot command > > line > > parameter 'vgacon.scrollback_persistent=1' or by setting > > VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT=y. > > > > Signed-off-by: Manuel Schölling > > Suggested-by: Bartlomiej Zolnierkiewicz > > +module_param_named(scrollback_persistent, scrollback_persistent, > > bool, 0000); > > +MODULE_PARM_DESC(scrollback_persistent, "Enable persistent > > scrollback for all vga consoles"); > > A command-line knob settable by the end-user is something more > persistent > than a config option.  As you're going to extend this code beyond > vgacon in > the near future, perhaps it'd be better to have a shared setting for > all > console drivers? Probably a good idea, but I'm struggling with the implementation a bit: I tried to run if (strstr(boot_command_line, "nopersistentscrollback")) {...} in vgacon_scrollback_startup() but I am getting WARNING: modpost: Found 2 section mismatch(es). when compiling. Probably because vgacon_scrollback_startup() is executed after init. I tried to find another way to implement a boot cmd line parameter but had no luck. If you/somebody could point me in the right direction, it would be very much appreciated. Thanks! Manuel