Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754816Ab0AZVvu (ORCPT ); Tue, 26 Jan 2010 16:51:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754679Ab0AZVvt (ORCPT ); Tue, 26 Jan 2010 16:51:49 -0500 Received: from terminus.zytor.com ([198.137.202.10]:60011 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754615Ab0AZVvs (ORCPT ); Tue, 26 Jan 2010 16:51:48 -0500 Message-ID: <4B5F6299.6090903@zytor.com> Date: Tue, 26 Jan 2010 13:46:01 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Pavel Machek CC: "Rafael J. Wysocki" , Alan Cox , Jesse Barnes , Len Brown , LKML , pm list , dri-devel@lists.sourceforge.net, Eric Anholt , airlied@linux.ie Subject: Re: [PATCH] PM / i915: Skip kernel VT switch during suspend/resume if KMS is used References: <201001240055.59479.rjw@sisk.pl> <201001252254.37635.rjw@sisk.pl> <20100126141726.GA1437@ucw.cz> <201001261947.46015.rjw@sisk.pl> <20100126145842.GA11295@ucw.cz> In-Reply-To: <20100126145842.GA11295@ucw.cz> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1242 Lines: 33 On 01/26/2010 06:58 AM, Pavel Machek wrote: >> >> That would have to be done using suspend notifiers and should depend on what >> driver actually controls the screen at the moment. And I guess the only case >> in which we actually _need_ to do the kernel VT switch is when the hardware >> is controlled by X and without KMS. > > We need vt switch when display is controlled by userland app directly > accessing hw. It may or may not be X (svgalib anyone?, > gtk-on-framebuffer? qtopia?). > > Ideally, userspace should explicitely tell us. KD_KERNEL_GRAPHICS > console mode? > It seems that the kernel would already know if it's in control of the mode switch, no? If userspace ever takes control and it doesn't already notify the kernel that it is taking over, we would seem to have a much bigger problem... > Plus the switch is needed for any graphics app using fbcon -- I do not > think we actually save the framebuffer over suspend. (This one should > probably be fixed). Quite. -hpa -- 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/