Re: [patch 3/3] VT: Bump font size limitation to 64x128 pixels

From: Jiri Slaby
Date: Tue Dec 06 2022 - 01:48:48 EST


On 05. 12. 22, 1:07, Samuel Thibault wrote:
This moves 32x32 font size limitation checking down to drivers, so that
fbcon can allow large fonts.

We still keep a limitation to 64x128 pixels so as to have a simple bounded
allocation for con_font_get and in the userland kbd tool. That glyph size
will however be enough to have 128x36 characters on a "16/9 8K display".

Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>

Index: linux-6.0/drivers/tty/vt/vt.c
===================================================================
--- linux-6.0.orig/drivers/tty/vt/vt.c
+++ linux-6.0/drivers/tty/vt/vt.c
@@ -4575,17 +4575,20 @@ void reset_palette(struct vc_data *vc)
...
-#define max_font_size 65536
+#define max_font_width 64
+#define max_font_height 128
+#define max_font_glyphs 512
+#define max_font_size (max_font_glyphs*max_font_width*max_font_height)

So this is 64K -> 4M switch. We should likely convert to kvmalloc() too.

regards,
--
js
suse labs