linux/drivers/video
Peilin Ye a1ac250a82 fbcon: Avoid using FNTCHARCNT() and hard-coded built-in font charcount
For user-provided fonts, the framebuffer layer is using a magic
negative-indexing macro, FNTCHARCNT(), to keep track of their number of
characters:

	#define FNTCHARCNT(fd)	(((int *)(fd))[-3])

For built-in fonts, it is using hard-coded values (256). This results in
something like the following:

		map.length = (ops->p->userfont) ?
			FNTCHARCNT(ops->p->fontdata) : 256;

This is unsatisfactory. In fact, there is already a `charcount` field in
our virtual console descriptor (see `struct console_font` inside `struct
vc_data`), let us use it:

		map.length = vc->vc_font.charcount;

Recently we added a `charcount` field to `struct font_desc`. Use it to set
`vc->vc_font.charcount` properly. The idea is:

  - We only use FNTCHARCNT() on `vc->vc_font.data` and `p->fontdata`.
    Assume FNTCHARCNT() is working as intended;
  - Whenever `vc->vc_font.data` is set, also set `vc->vc_font.charcount`
    properly;
  - We can now replace `FNTCHARCNT(vc->vc_font.data)` with
    `vc->vc_font.charcount`;
  - Since `p->fontdata` always point to the same font data buffer with
    `vc->vc_font.data`, we can also replace `FNTCHARCNT(p->fontdata)` with
    `vc->vc_font.charcount`.

In conclusion, set `vc->vc_font.charcount` properly in fbcon_startup(),
fbcon_init(), fbcon_set_disp() and fbcon_do_set_font(), then replace
FNTCHARCNT() with `vc->vc_font.charcount`. No more if-else between
negative-indexing macros and hard-coded values.

Do not include <linux/font.h> in fbcon_rotate.c and tileblit.c, since they
no longer need it.

Depends on patch "Fonts: Add charcount field to font_desc".

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/e460a5780e54e3022661d5f09555144583b4cc59.1605169912.git.yepeilin.cs@gmail.com
2020-11-16 16:33:12 +01:00
..
backlight - New Drivers 2020-10-14 15:59:42 -07:00
console parisc/sticore: Avoid hard-coding built-in font charcount 2020-11-16 16:31:58 +01:00
fbdev fbcon: Avoid using FNTCHARCNT() and hard-coded built-in font charcount 2020-11-16 16:33:12 +01:00
logo .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
display_timing.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
hdmi.c drivers/video: Fix -Wstringop-truncation in hdmi.c 2020-11-03 10:38:06 +01:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile
of_display_timing.c video: of: display_timing: Don't yell if no timing node is present 2019-07-26 16:32:26 +02:00
of_videomode.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
vgastate.c Video: vgastate: fixed a spacing coding style 2018-10-08 12:57:35 +02:00
videomode.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00