From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prarit Bhargava Date: Thu, 10 Jan 2019 18:46:31 +0000 Subject: Re: [PATCH v3] fbcon: Silence fbcon logo on 'quiet' boots Message-Id: <0284fa5c-125e-9b1d-64c6-f7cbbfadcd1b@redhat.com> List-Id: References: <20181030154419.2889-1-prarit@redhat.com> <3de54c0d-3e9b-769f-5cc6-e69dbb399426@samsung.com> <20190102160536.h46ehoymo4sh6apz@pathway.suse.cz> In-Reply-To: <20190102160536.h46ehoymo4sh6apz@pathway.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Petr Mladek , Bartlomiej Zolnierkiewicz Cc: Yisheng Xie , linux-fbdev@vger.kernel.org, Kees Cook , Sergey Senozhatsky , Daniel Vetter , Steven Rostedt , Marko Myllynen , Hans de Goede , dri-devel@lists.freedesktop.org, Thierry Reding On 1/2/19 11:05 AM, Petr Mladek wrote: > On Thu 2018-12-20 17:31:57, Bartlomiej Zolnierkiewicz wrote: >> >> [ added Petr & Sergey to Cc: ] >> >> Hi, >> >> On 10/30/2018 04:44 PM, Prarit Bhargava wrote: >>> On text-based systems the 'quiet' boot option will show printk levels >>> higher than CONSOLE_LOGLEVEL_QUIET. The displaying of the Tux logo >>> during boot can cause some consoles to lose display data and as a result >>> confuse the end user. >>> >>> Do not display the Tux logo on systems that are in 'quiet' boot. >>> >>> v2: It helps to commit all my changes before sending them. Remove extra >>> bracket. >>> v3: buildbot error fix: fbcon can be built as part of a module so export console_printk >>> >>> Signed-off-by: Prarit Bhargava >>> Cc: Hans de Goede >>> Cc: Marko Myllynen >>> Cc: Steven Rostedt (VMware) >>> Cc: Bartlomiej Zolnierkiewicz >>> Cc: Kees Cook >>> Cc: Daniel Vetter >>> Cc: Thierry Reding >>> Cc: Yisheng Xie >>> Cc: dri-devel@lists.freedesktop.org >>> --- >>> drivers/video/fbdev/core/fbcon.c | 13 ++++++++----- >>> kernel/printk/printk.c | 1 + >>> 2 files changed, 9 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c >>> index 8958ccc8b1ac..08e092eaf45c 100644 >>> --- a/drivers/video/fbdev/core/fbcon.c >>> +++ b/drivers/video/fbdev/core/fbcon.c >>> @@ -649,11 +649,14 @@ static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info, >>> kfree(save); >>> } >>> >>> + if (logo_shown = FBCON_LOGO_DONTSHOW) >>> + return; >>> + >>> if (logo_lines > vc->vc_bottom) { >>> logo_shown = FBCON_LOGO_CANSHOW; >>> printk(KERN_INFO >>> "fbcon_init: disable boot-logo (boot-logo bigger than screen).\n"); >>> - } else if (logo_shown != FBCON_LOGO_DONTSHOW) { >>> + } else { >>> logo_shown = FBCON_LOGO_DRAW; >>> vc->vc_top = logo_lines; >>> } >>> @@ -1051,7 +1054,7 @@ static void fbcon_init(struct vc_data *vc, int init) >>> struct vc_data **default_mode = vc->vc_display_fg; >>> struct vc_data *svc = *default_mode; >>> struct display *t, *p = &fb_display[vc->vc_num]; >>> - int logo = 1, new_rows, new_cols, rows, cols, charcnt = 256; >>> + int new_rows, new_cols, rows, cols, charcnt = 256; >>> int cap, ret; >>> >>> if (info_idx = -1 || info = NULL) >>> @@ -1059,9 +1062,9 @@ static void fbcon_init(struct vc_data *vc, int init) >>> >>> cap = info->flags; >>> >>> - if (vc != svc || logo_shown = FBCON_LOGO_DONTSHOW || >>> + if (vc != svc || console_loglevel <= CONSOLE_LOGLEVEL_QUIET || >>> (info->fix.type = FB_TYPE_TEXT)) >>> - logo = 0; >>> + logo_shown = FBCON_LOGO_DONTSHOW; >> >> "logo" variable removal is an unrelated change which actually >> changes the code behavior ("logo_shown" will be now modified >> also for "vc != svc" and "info->fix.type = FB_TYPE_TEXT" cases). >> >> Please either drop it or explain in the patch description why >> it is a safe thing to do. > Hi Petr, I will drop it from the patch. P. > Good question! I am not familiar with fbcon code but it seems > that there might be more instances and they share the behavior > via this variable. > > Note that console_loglevel might get modified at anytime. What if > the first fbcon was initialized with a different loglevel? > > >>> if (var_to_display(p, &info->var, info)) >>> return; >>> @@ -1176,7 +1179,7 @@ static void fbcon_init(struct vc_data *vc, int init) >>> } else >>> vc_resize(vc, new_cols, new_rows); >>> >>> - if (logo) >>> + if (logo_shown != FBCON_LOGO_DONTSHOW) >>> fbcon_prepare_logo(vc, info, cols, rows, new_cols, new_rows); >>> >>> if (vc = svc && softback_buf) >>> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c >>> index b77150ad1965..391e390feac9 100644 >>> --- a/kernel/printk/printk.c >>> +++ b/kernel/printk/printk.c >>> @@ -66,6 +66,7 @@ int console_printk[4] = { >>> CONSOLE_LOGLEVEL_MIN, /* minimum_console_loglevel */ >>> CONSOLE_LOGLEVEL_DEFAULT, /* default_console_loglevel */ >>> }; >>> +EXPORT_SYMBOL(console_printk); >> >> You need printk Maintainers Ack on it. > > I am fine with the added export (as a printk maintainer). > > Best Regards, > Petr >