Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966610AbWKTUGP (ORCPT ); Mon, 20 Nov 2006 15:06:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966611AbWKTUGP (ORCPT ); Mon, 20 Nov 2006 15:06:15 -0500 Received: from smtp.osdl.org ([65.172.181.25]:2747 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S966610AbWKTUGO (ORCPT ); Mon, 20 Nov 2006 15:06:14 -0500 Date: Mon, 20 Nov 2006 12:05:21 -0800 From: Andrew Morton To: James Simmons Cc: linux-fbdev-devel@lists.sourceforge.net, Tero Roponen , linux-kernel@vger.kernel.org Subject: Re: [Linux-fbdev-devel] fb: modedb uses wrong default_mode Message-Id: <20061120120521.68724342.akpm@osdl.org> In-Reply-To: References: <20061115152952.0e92c50d.akpm@osdl.org> <20061115234456.GB3674@cosmic.amd.com> <20061117124013.b6e4183d.akpm@osdl.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1613 Lines: 52 On Mon, 20 Nov 2006 16:48:05 +0000 (GMT) James Simmons wrote: > > > db = modedb; > > > dbsize = ARRAY_SIZE(modedb); > > > > > > if (!default_mode) > > > default_mode = &db[DEFAULT_MODEDB_INDEX]; > > > if (!default_bpp) > > > default_bpp = 8; > > > > > > db will always be set. > > > > I think we do need dbsize, and that the code which I have now: > > I really don't trust dbsize. The driver writer can pass in the wrong > number. That would be a bug. > Whereas ARRAY_SIZE will always be correct. Lets take the position > that we use dbsize then we need to test if dbsize is greater than the > really size of the modedb. The dbsize parameter was for the days before we > had ARRAY_SIZE. > > > int fb_find_mode(struct fb_var_screeninfo *var, > > struct fb_info *info, const char *mode_option, > > const struct fb_videomode *db, unsigned int dbsize, > > const struct fb_videomode *default_mode, > > unsigned int default_bpp) > > { > > int i; > > > > /* Set up defaults */ > > if (!db) { > > db = modedb; > > dbsize = ARRAY_SIZE(modedb); > > } > > if (dbsize > ARRAY_SIZE(db)) > dbsize = ARRAY_SIZE(db); We can't do ARRAY_SIZE on a random pointer like this: the compiler needs to see the full definition of the array itself, and that is back in the caller's compilation unit. - 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/