linux-kernel - [PATCH v3 2/3] fbdev: fbmem: allow overriding the number of bootup logos

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Date:   Tue, 27 Aug 2019 11:09:21 +0000
From:   Peter Rosin <peda@...ntia.se>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Peter Rosin <peda@...ntia.se>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Jonathan Corbet <corbet@....net>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "linux-fbdev@...r.kernel.org" <linux-fbdev@...r.kernel.org>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Subject: [PATCH v3 2/3] fbdev: fbmem: allow overriding the number of bootup
 logos

Probably most useful if you want no logo at all, or if you only want one
logo regardless of how many CPU cores you have.

Signed-off-by: Peter Rosin <peda@...ntia.se>
---
 Documentation/fb/fbcon.rst       |  5 +++++
 drivers/video/fbdev/core/fbcon.c |  7 +++++++
 drivers/video/fbdev/core/fbmem.c | 12 +++++++++---
 include/linux/fb.h               |  1 +
 4 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/Documentation/fb/fbcon.rst b/Documentation/fb/fbcon.rst
index 65ba40255137..e57a3d1d085a 100644
--- a/Documentation/fb/fbcon.rst
+++ b/Documentation/fb/fbcon.rst
@@ -174,6 +174,11 @@ C. Boot options
 	displayed due to multiple CPUs, the collected line of logos is moved
 	as a whole.
 
+9. fbcon=logo-count:<n>
+
+	The value 'n' overrides the number of bootup logos. 0 disables the
+	logo, and -1 gives the default which is the number of online CPUs.
+
 C. Attaching, Detaching and Unloading
 
 Before going on to how to attach, detach and unload the framebuffer console, an
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index c9235a2f42f8..bb6ae995c2e5 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -536,6 +536,13 @@ static int __init fb_console_setup(char *this_opt)
 				fb_center_logo = true;
 			continue;
 		}
+
+		if (!strncmp(options, "logo-count:", 11)) {
+			options += 11;
+			if (*options)
+				fb_logo_count = simple_strtol(options, &options, 0);
+			continue;
+		}
 	}
 	return 1;
 }
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 64dd732021d8..c7ddcb72025b 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -56,6 +56,8 @@ EXPORT_SYMBOL(num_registered_fb);
 bool fb_center_logo __read_mostly;
 EXPORT_SYMBOL(fb_center_logo);
 
+int fb_logo_count __read_mostly = -1;
+
 static struct fb_info *get_fb_info(unsigned int idx)
 {
 	struct fb_info *fb_info;
@@ -620,7 +622,7 @@ int fb_prepare_logo(struct fb_info *info, int rotate)
 	memset(&fb_logo, 0, sizeof(struct logo_data));
 
 	if (info->flags & FBINFO_MISC_TILEBLITTING ||
-	    info->fbops->owner)
+	    info->fbops->owner || !fb_logo_count)
 		return 0;
 
 	if (info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
@@ -686,10 +688,14 @@ int fb_prepare_logo(struct fb_info *info, int rotate)
 
 int fb_show_logo(struct fb_info *info, int rotate)
 {
+	unsigned int count;
 	int y;
 
-	y = fb_show_logo_line(info, rotate, fb_logo.logo, 0,
-			      num_online_cpus());
+	if (!fb_logo_count)
+		return 0;
+
+	count = fb_logo_count < 0 ? num_online_cpus() : fb_logo_count;
+	y = fb_show_logo_line(info, rotate, fb_logo.logo, 0, count);
 	y = fb_show_extra_logos(info, y, rotate);
 
 	return y;
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 303771264644..e37f72b2efca 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -630,6 +630,7 @@ extern int fb_new_modelist(struct fb_info *info);
 extern struct fb_info *registered_fb[FB_MAX];
 extern int num_registered_fb;
 extern bool fb_center_logo;
+extern int fb_logo_count;
 extern struct class *fb_class;
 
 #define for_each_registered_fb(i)		\
-- 
2.11.0