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 24542C433F5 for ; Sun, 6 Feb 2022 00:31:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232876AbiBFAbc (ORCPT ); Sat, 5 Feb 2022 19:31:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229983AbiBFAbc (ORCPT ); Sat, 5 Feb 2022 19:31:32 -0500 Received: from mx2.smtp.larsendata.com (mx2.smtp.larsendata.com [91.221.196.228]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB49AC061348 for ; Sat, 5 Feb 2022 16:31:30 -0800 (PST) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx2.smtp.larsendata.com (Halon) with ESMTPS id 8640be1c-8536-11ec-ac19-0050568cd888; Thu, 03 Feb 2022 21:16:16 +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 6844B194B5E; Thu, 3 Feb 2022 22:15:16 +0100 (CET) Date: Thu, 3 Feb 2022 22:15:14 +0100 X-Report-Abuse-To: abuse@mxhotel.dk From: Sam Ravnborg To: Daniel Vetter Cc: 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: <20220131210552.482606-12-daniel.vetter@ffwll.ch> Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org 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? > - if (!found && newinfo->fbops->fb_release) > - newinfo->fbops->fb_release(newinfo, 0); > - if (!found) > - module_put(newinfo->fbops->owner); > - err = -ENODEV; > - } > + fbcon_release(oldinfo); > > - if (!err) { > - fbcon_del_cursor_work(oldinfo); > - kfree(ops->cursor_state.mask); > - kfree(ops->cursor_data); > - kfree(ops->cursor_src); > - kfree(ops->fontbuffer); > - kfree(oldinfo->fbcon_par); > - oldinfo->fbcon_par = NULL; > - module_put(oldinfo->fbops->owner); > - /* > - If oldinfo and newinfo are driving the same hardware, > - the fb_release() method of oldinfo may attempt to > - restore the hardware state. This will leave the > - newinfo in an undefined state. Thus, a call to > - fb_set_par() may be needed for the newinfo. > - */ > - if (newinfo && newinfo->fbops->fb_set_par) { > - ret = newinfo->fbops->fb_set_par(newinfo); > + fbcon_del_cursor_work(oldinfo); > + kfree(ops->cursor_state.mask); > + kfree(ops->cursor_data); > + kfree(ops->cursor_src); > + kfree(ops->fontbuffer); > + kfree(oldinfo->fbcon_par); > + oldinfo->fbcon_par = NULL; These all look like candidates to stuff into fbcon_release() That would drop the nice symmetry but make it more consistent. I think we miss freeing ops->cursor_data in fbcon_exit(), but I did not follow all the code. With my ramblings considered the patch is Acked-by: Sam Ravnborg Sam > + /* > + If oldinfo and newinfo are driving the same hardware, > + the fb_release() method of oldinfo may attempt to > + restore the hardware state. This will leave the > + newinfo in an undefined state. Thus, a call to > + fb_set_par() may be needed for the newinfo. > + */ > + if (newinfo && newinfo->fbops->fb_set_par) { > + ret = newinfo->fbops->fb_set_par(newinfo); > > - if (ret) > - printk(KERN_ERR "con2fb_release_oldinfo: " > - "detected unhandled fb_set_par error, " > - "error code %d\n", ret); > - } > + if (ret) > + printk(KERN_ERR "con2fb_release_oldinfo: " > + "detected unhandled fb_set_par error, " > + "error code %d\n", ret); > } > > - return err; > + return 0; > } > > static void con2fb_init_display(struct vc_data *vc, struct fb_info *info, > @@ -917,7 +924,6 @@ static const char *fbcon_startup(void) > struct fbcon_display *p = &fb_display[fg_console]; > struct vc_data *vc = vc_cons[fg_console].d; > const struct font_desc *font = NULL; > - struct module *owner; > struct fb_info *info = NULL; > struct fbcon_ops *ops; > int rows, cols; > @@ -936,17 +942,12 @@ static const char *fbcon_startup(void) > if (!info) > return NULL; > > - owner = info->fbops->owner; > - if (!try_module_get(owner)) > + if (fbcon_open(info)) > return NULL; > - if (info->fbops->fb_open && info->fbops->fb_open(info, 0)) { > - module_put(owner); > - return NULL; > - } > > ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL); > if (!ops) { > - module_put(owner); > + fbcon_release(info); > return NULL; > } > > @@ -3331,10 +3332,6 @@ static void fbcon_exit(void) > } > > if (mapped) { > - if (info->fbops->fb_release) > - info->fbops->fb_release(info, 0); > - module_put(info->fbops->owner); > - > if (info->fbcon_par) { > struct fbcon_ops *ops = info->fbcon_par; > > @@ -3344,6 +3341,8 @@ static void fbcon_exit(void) > kfree(info->fbcon_par); > info->fbcon_par = NULL; > } > + > + fbcon_release(info); > } > } > } > -- > 2.33.0