From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: deprecating fix->mmio_start and smem_start Date: Tue, 22 Apr 2008 20:44:20 +0200 (CEST) Message-ID: References: <1208827046.9640.73.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1JoNTl-0002sK-B5 for linux-fbdev-devel@lists.sourceforge.net; Tue, 22 Apr 2008 11:44:33 -0700 Received: from wilson.telenet-ops.be ([195.130.132.42]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1JoNTc-0004v8-GI for linux-fbdev-devel@lists.sourceforge.net; Tue, 22 Apr 2008 11:44:28 -0700 In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: "Scott D. Davilla" Cc: linux-fbdev-devel@lists.sourceforge.net On Tue, 22 Apr 2008, Scott D. Davilla wrote: > > On Tue, 22 Apr 2008, Scott D. Davilla wrote: > > > >On Tue, 22 Apr 2008, Benjamin Herrenschmidt wrote: > > > >> We currently have a problem with those two members of struct > > > >> fb_fix_screeninfo. The struct contains an "unsigned long" which means > > > >> that: > > > >> > > > >> - 64 bits kernels with 32 bits userspace can't pass a complete > > > address > > > >> - 32 bits machines with 64 bits resource_size_t can't pass a complete > > > >> address > > > >> - The structure isn't even properly padded to be 32/64 bits neutral > > > in > > > >> the first place. > > > >> > > > > > We could define new versions of the struct with new get/set ioctls, > > > >> or we could try to just deprecate those fields. What do you guys > > > think ? > > > > > > > >As userspace doesn't really need those fields[1], we can easily > > > >deprecate them. > > > > > > kexec uses FBIOGET_FSCREENINFO and FBIOGET_VSCREENINFO. So if these > > > ioctls changes, it will possibly break kexec under vesafb and efifb. > > > > Does kexec use the smem_start and mmio_start fields of > > fb_fix_screeninfo? > > > > In "kexec/arch/i386/x86-linux-setup.c", the routine "setup_linux_vesafb" uses > smem_start, smem_len, and line_length. > > This is used for vesafb and efifb framebuffer kernel boot param setup. This is > required for PC hardware that do not contain a PC-BIOS and need the bootloader > to setup the kernel video boot params. OK, but the problem doesn't show up on x86-32 (no >32-bit physical addresses yet), as x86_linux_param_header.lfb_base is uint32_t and there's no way it's gonna change. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone