From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12EABC433EF for ; Tue, 8 Feb 2022 18:24:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384819AbiBHSYJ (ORCPT ); Tue, 8 Feb 2022 13:24:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1384814AbiBHSYJ (ORCPT ); Tue, 8 Feb 2022 13:24:09 -0500 Received: from mx1.smtp.larsendata.com (mx1.smtp.larsendata.com [91.221.196.215]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18639C061579 for ; Tue, 8 Feb 2022 10:24:07 -0800 (PST) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx1.smtp.larsendata.com (Halon) with ESMTPS id 72537d88-890c-11ec-b20b-0050568c148b; Tue, 08 Feb 2022 18:25:09 +0000 (UTC) Received: from ravnborg.org (80-162-45-141-cable.dk.customer.tdc.net [80.162.45.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sam@ravnborg.org) by mail01.mxhotel.dk (Postfix) with ESMTPSA id 16C32194BDF; Tue, 8 Feb 2022 19:24:06 +0100 (CET) Date: Tue, 8 Feb 2022 19:24:03 +0100 X-Report-Abuse-To: abuse@mxhotel.dk From: Sam Ravnborg To: DRI Development , linux-fbdev@vger.kernel.org, Du Cheng , Tetsuo Handa , Intel Graphics Development , LKML , Claudio Suarez , Greg Kroah-Hartman , Daniel Vetter Subject: Re: [PATCH 11/21] fbcon: Extract fbcon_open/release helpers Message-ID: References: <20220131210552.482606-1-daniel.vetter@ffwll.ch> <20220131210552.482606-12-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Hi Daniel, On Tue, Feb 08, 2022 at 02:48:29PM +0100, Daniel Vetter wrote: > On Thu, Feb 03, 2022 at 10:15:14PM +0100, Sam Ravnborg wrote: > > Hi Daniel, > > > > On Mon, Jan 31, 2022 at 10:05:42PM +0100, Daniel Vetter wrote: > > > There's two minor behaviour changes in here: > > > - in error paths we now consistently call fb_ops->fb_release > > > - fb_release really can't fail (fbmem.c ignores it too) and there's no > > > reasonable cleanup we can do anyway. > > > > > > Signed-off-by: Daniel Vetter > > > Cc: Daniel Vetter > > > Cc: Claudio Suarez > > > Cc: Greg Kroah-Hartman > > > Cc: Tetsuo Handa > > > Cc: Du Cheng > > > --- > > > drivers/video/fbdev/core/fbcon.c | 107 +++++++++++++++---------------- > > > 1 file changed, 53 insertions(+), 54 deletions(-) > > > > > > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c > > > index fa30e1909164..eea2ee14b64c 100644 > > > --- a/drivers/video/fbdev/core/fbcon.c > > > +++ b/drivers/video/fbdev/core/fbcon.c > > > @@ -680,19 +680,37 @@ static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount) > > > > > > #endif /* CONFIG_MISC_TILEBLITTING */ > > > > > > +static int fbcon_open(struct fb_info *info) > > > +{ > > > + if (!try_module_get(info->fbops->owner)) > > > + return -ENODEV; > > > + > > > + if (info->fbops->fb_open && > > > + info->fbops->fb_open(info, 0)) { > > > + module_put(info->fbops->owner); > > > + return -ENODEV; > > > + } > > > + > > > + return 0; > > > +} > > > + > > > +static void fbcon_release(struct fb_info *info) > > > +{ > > > + if (info->fbops->fb_release) > > > + info->fbops->fb_release(info, 0); > > > + > > > + module_put(info->fbops->owner); > > > +} > > > > > > static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, > > > int unit, int oldidx) > > > { > > > struct fbcon_ops *ops = NULL; > > > - int err = 0; > > > - > > > - if (!try_module_get(info->fbops->owner)) > > > - err = -ENODEV; > > > + int err; > > > > > > - if (!err && info->fbops->fb_open && > > > - info->fbops->fb_open(info, 0)) > > > - err = -ENODEV; > > > + err = fbcon_open(info); > > > + if (err) > > > + return err; > > > > > > if (!err) { > > > ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > > > @@ -713,7 +731,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info, > > > > > > if (err) { > > > con2fb_map[unit] = oldidx; > > > - module_put(info->fbops->owner); > > > + fbcon_release(info); > > > } > > > > > > return err; > > > @@ -724,45 +742,34 @@ static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo, > > > int oldidx, int found) > > > { > > > struct fbcon_ops *ops = oldinfo->fbcon_par; > > > - int err = 0, ret; > > > + int ret; > > > > > > - if (oldinfo->fbops->fb_release && > > > - oldinfo->fbops->fb_release(oldinfo, 0)) { > > > - con2fb_map[unit] = oldidx; > > The old code assigns con2fb_map[unit] before is calls > > newinfo->fbops->fb_release). > > I wonder if there can be any callback to fbcon where the value > > of con2fb_map[unit] matters? > > It's all protected by console_lock, so other threads cannot see the > inconsistent state. > > Essentially everything in fbcon.c is protected by console_lock(). > > Do you want me to hammer this in somewhere (maybe in the commit message), > or good enough for your ack? No need to spell it out more. Add my a-b and apply it. Sam