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 EFB09C433FE for ; Tue, 8 Feb 2022 18:27:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384933AbiBHS1i (ORCPT ); Tue, 8 Feb 2022 13:27:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242067AbiBHS1h (ORCPT ); Tue, 8 Feb 2022 13:27:37 -0500 Received: from mx1.smtp.larsendata.com (mx1.smtp.larsendata.com [91.221.196.215]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D42FC061576 for ; Tue, 8 Feb 2022 10:27:35 -0800 (PST) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx1.smtp.larsendata.com (Halon) with ESMTPS id eed6468f-890c-11ec-b20b-0050568c148b; Tue, 08 Feb 2022 18:28:38 +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 0370B194B43; Tue, 8 Feb 2022 19:27:34 +0100 (CET) Date: Tue, 8 Feb 2022 19:27:32 +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 18/21] fbcon: untangle fbcon_exit Message-ID: References: <20220131210552.482606-1-daniel.vetter@ffwll.ch> <20220131210552.482606-19-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-kernel@vger.kernel.org On Tue, Feb 08, 2022 at 02:58:21PM +0100, Daniel Vetter wrote: > On Fri, Feb 04, 2022 at 09:06:38PM +0100, Sam Ravnborg wrote: > > Hi Daniel, > > > > On Mon, Jan 31, 2022 at 10:05:49PM +0100, Daniel Vetter wrote: > > > There's a bunch of confusions going on here: > > > - The deferred fbcon setup notifier should only be cleaned up from > > > fb_console_exit(), to be symmetric with fb_console_init() > > > - We also need to make sure we don't race with the work, which means > > > temporarily dropping the console lock (or we can deadlock) > > > - That also means no point in clearing deferred_takeover, we are > > > unloading everything anyway. > > > - Finally rename fbcon_exit to fbcon_release_all and move it, since > > > that's what's it doing when being called from consw->con_deinit > > > through fbcon_deinit. > > > > > > Signed-off-by: Daniel Vetter > > > Cc: Daniel Vetter > > > Cc: Greg Kroah-Hartman > > > Cc: Claudio Suarez > > > Cc: Du Cheng > > > Cc: Tetsuo Handa > > > --- > > > drivers/video/fbdev/core/fbcon.c | 63 ++++++++++++++++---------------- > > > 1 file changed, 32 insertions(+), 31 deletions(-) > > > > > > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c > > > index 5c14e24d14a1..22581952b4fd 100644 > > > --- a/drivers/video/fbdev/core/fbcon.c > > > +++ b/drivers/video/fbdev/core/fbcon.c > > > @@ -185,7 +185,6 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var, > > > int unit); > > > static void fbcon_modechanged(struct fb_info *info); > > > static void fbcon_set_all_vcs(struct fb_info *info); > > > -static void fbcon_exit(void); > > > > > > static struct device *fbcon_device; > > > > > > @@ -1149,6 +1148,27 @@ static void fbcon_free_font(struct fbcon_display *p, bool freefont) > > > > > > static void set_vc_hi_font(struct vc_data *vc, bool set); > > > > > > +static void fbcon_release_all(void) > > > +{ > > > + struct fb_info *info; > > > + int i, j, mapped; > > > + > > > + for_each_registered_fb(i) { > > > + mapped = 0; > > > + info = registered_fb[i]; > > > + > > > + for (j = first_fb_vc; j <= last_fb_vc; j++) { > > > + if (con2fb_map[j] == i) { > > > + mapped = 1; > > > + con2fb_map[j] = -1; > > > + } > > > + } > > > + > > > + if (mapped) > > > + fbcon_release(info); > > > + } > > > +} > > > + > > > static void fbcon_deinit(struct vc_data *vc) > > > { > > > struct fbcon_display *p = &fb_display[vc->vc_num]; > > > @@ -1188,7 +1208,7 @@ static void fbcon_deinit(struct vc_data *vc) > > > set_vc_hi_font(vc, false); > > > > > > if (!con_is_bound(&fb_con)) > > > - fbcon_exit(); > > > + fbcon_release_all(); > > > > > > if (vc->vc_num == logo_shown) > > > logo_shown = FBCON_LOGO_CANSHOW; > > > @@ -3316,34 +3336,6 @@ static void fbcon_start(void) > > > #endif > > > } > > > > > > -static void fbcon_exit(void) > > > -{ > > > - struct fb_info *info; > > > - int i, j, mapped; > > > - > > > -#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > > > - if (deferred_takeover) { > > > - dummycon_unregister_output_notifier(&fbcon_output_nb); > > > - deferred_takeover = false; > > > - } > > > -#endif > > > - > > > - for_each_registered_fb(i) { > > > - mapped = 0; > > > - info = registered_fb[i]; > > > - > > > - for (j = first_fb_vc; j <= last_fb_vc; j++) { > > > - if (con2fb_map[j] == i) { > > > - mapped = 1; > > > - con2fb_map[j] = -1; > > > - } > > > - } > > > - > > > - if (mapped) > > > - fbcon_release(info); > > > - } > > > -} > > > - > > > void __init fb_console_init(void) > > > { > > > int i; > > > @@ -3383,10 +3375,19 @@ static void __exit fbcon_deinit_device(void) > > > > > > void __exit fb_console_exit(void) > > > { > > > +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > > > + console_lock(); > > > + if (deferred_takeover) > > > + dummycon_unregister_output_notifier(&fbcon_output_nb); > > > + console_unlock(); > > > + > > > + cancel_work_sync(&fbcon_deferred_takeover_work); > > > +#endif > > > + > > > console_lock(); > > > fbcon_deinit_device(); > > > device_destroy(fb_class, MKDEV(0, 0)); > > > - fbcon_exit(); > > > + > > We loose the call to fbcon_release_all() here. > > We have part of the old fbcon_exit() above, but miss the release parts. > > > > Maybe I missed something obvious? > > Ah yes that's the entire point of this change. The release_all in the > fbcon exit path was only needed when fbcon was a separate module > indepedent from core fb.ko. Which means it was possible to unload fbcon > while having fbdev drivers registered. > > But since we've merged them that has become impossible, so by the time the > fb.ko module can be unloaded, there's guaranteed to be no fbdev drivers > left. And hence removing them is pointless. Makes sense, thanks for the explanation. > > Ack with that explainer added to the commit message? Yes, then it is Acked-by: Sam Ravnborg 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 27A06C433F5 for ; Tue, 8 Feb 2022 18:27:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 559DA10E9D2; Tue, 8 Feb 2022 18:27:38 +0000 (UTC) Received: from mx1.smtp.larsendata.com (mx1.smtp.larsendata.com [91.221.196.215]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4682D10E9CE for ; Tue, 8 Feb 2022 18:27:36 +0000 (UTC) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx1.smtp.larsendata.com (Halon) with ESMTPS id eed6468f-890c-11ec-b20b-0050568c148b; Tue, 08 Feb 2022 18:28:38 +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 0370B194B43; Tue, 8 Feb 2022 19:27:34 +0100 (CET) Date: Tue, 8 Feb 2022 19:27:32 +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 Message-ID: References: <20220131210552.482606-1-daniel.vetter@ffwll.ch> <20220131210552.482606-19-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Intel-gfx] [PATCH 18/21] fbcon: untangle fbcon_exit X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Feb 08, 2022 at 02:58:21PM +0100, Daniel Vetter wrote: > On Fri, Feb 04, 2022 at 09:06:38PM +0100, Sam Ravnborg wrote: > > Hi Daniel, > > > > On Mon, Jan 31, 2022 at 10:05:49PM +0100, Daniel Vetter wrote: > > > There's a bunch of confusions going on here: > > > - The deferred fbcon setup notifier should only be cleaned up from > > > fb_console_exit(), to be symmetric with fb_console_init() > > > - We also need to make sure we don't race with the work, which means > > > temporarily dropping the console lock (or we can deadlock) > > > - That also means no point in clearing deferred_takeover, we are > > > unloading everything anyway. > > > - Finally rename fbcon_exit to fbcon_release_all and move it, since > > > that's what's it doing when being called from consw->con_deinit > > > through fbcon_deinit. > > > > > > Signed-off-by: Daniel Vetter > > > Cc: Daniel Vetter > > > Cc: Greg Kroah-Hartman > > > Cc: Claudio Suarez > > > Cc: Du Cheng > > > Cc: Tetsuo Handa > > > --- > > > drivers/video/fbdev/core/fbcon.c | 63 ++++++++++++++++---------------- > > > 1 file changed, 32 insertions(+), 31 deletions(-) > > > > > > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c > > > index 5c14e24d14a1..22581952b4fd 100644 > > > --- a/drivers/video/fbdev/core/fbcon.c > > > +++ b/drivers/video/fbdev/core/fbcon.c > > > @@ -185,7 +185,6 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var, > > > int unit); > > > static void fbcon_modechanged(struct fb_info *info); > > > static void fbcon_set_all_vcs(struct fb_info *info); > > > -static void fbcon_exit(void); > > > > > > static struct device *fbcon_device; > > > > > > @@ -1149,6 +1148,27 @@ static void fbcon_free_font(struct fbcon_display *p, bool freefont) > > > > > > static void set_vc_hi_font(struct vc_data *vc, bool set); > > > > > > +static void fbcon_release_all(void) > > > +{ > > > + struct fb_info *info; > > > + int i, j, mapped; > > > + > > > + for_each_registered_fb(i) { > > > + mapped = 0; > > > + info = registered_fb[i]; > > > + > > > + for (j = first_fb_vc; j <= last_fb_vc; j++) { > > > + if (con2fb_map[j] == i) { > > > + mapped = 1; > > > + con2fb_map[j] = -1; > > > + } > > > + } > > > + > > > + if (mapped) > > > + fbcon_release(info); > > > + } > > > +} > > > + > > > static void fbcon_deinit(struct vc_data *vc) > > > { > > > struct fbcon_display *p = &fb_display[vc->vc_num]; > > > @@ -1188,7 +1208,7 @@ static void fbcon_deinit(struct vc_data *vc) > > > set_vc_hi_font(vc, false); > > > > > > if (!con_is_bound(&fb_con)) > > > - fbcon_exit(); > > > + fbcon_release_all(); > > > > > > if (vc->vc_num == logo_shown) > > > logo_shown = FBCON_LOGO_CANSHOW; > > > @@ -3316,34 +3336,6 @@ static void fbcon_start(void) > > > #endif > > > } > > > > > > -static void fbcon_exit(void) > > > -{ > > > - struct fb_info *info; > > > - int i, j, mapped; > > > - > > > -#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > > > - if (deferred_takeover) { > > > - dummycon_unregister_output_notifier(&fbcon_output_nb); > > > - deferred_takeover = false; > > > - } > > > -#endif > > > - > > > - for_each_registered_fb(i) { > > > - mapped = 0; > > > - info = registered_fb[i]; > > > - > > > - for (j = first_fb_vc; j <= last_fb_vc; j++) { > > > - if (con2fb_map[j] == i) { > > > - mapped = 1; > > > - con2fb_map[j] = -1; > > > - } > > > - } > > > - > > > - if (mapped) > > > - fbcon_release(info); > > > - } > > > -} > > > - > > > void __init fb_console_init(void) > > > { > > > int i; > > > @@ -3383,10 +3375,19 @@ static void __exit fbcon_deinit_device(void) > > > > > > void __exit fb_console_exit(void) > > > { > > > +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > > > + console_lock(); > > > + if (deferred_takeover) > > > + dummycon_unregister_output_notifier(&fbcon_output_nb); > > > + console_unlock(); > > > + > > > + cancel_work_sync(&fbcon_deferred_takeover_work); > > > +#endif > > > + > > > console_lock(); > > > fbcon_deinit_device(); > > > device_destroy(fb_class, MKDEV(0, 0)); > > > - fbcon_exit(); > > > + > > We loose the call to fbcon_release_all() here. > > We have part of the old fbcon_exit() above, but miss the release parts. > > > > Maybe I missed something obvious? > > Ah yes that's the entire point of this change. The release_all in the > fbcon exit path was only needed when fbcon was a separate module > indepedent from core fb.ko. Which means it was possible to unload fbcon > while having fbdev drivers registered. > > But since we've merged them that has become impossible, so by the time the > fb.ko module can be unloaded, there's guaranteed to be no fbdev drivers > left. And hence removing them is pointless. Makes sense, thanks for the explanation. > > Ack with that explainer added to the commit message? Yes, then it is Acked-by: Sam Ravnborg