kernel/linux.git/drivers/video/fbdev/core/fbcon_rotate.c, branch v7.1

fbcon: Put font-rotation state into separate struct

2026-04-07T15:38:07+00:00

Move all temporary state of the font-rotation code into the struct rotated in struct fbcon_par. Protect it with the Kconfig symbol CONFIG_FRAMEBUFFER_CONSOLE_ROTATION. Avoids mixing it up with fbcon's regular state. v2: - fix typos Signed-off-by: Thomas Zimmermann Signed-off-by: Helge Deller

lib/fonts: Implement font rotation

2026-04-07T15:38:07+00:00

Move the core of fbcon's font-rotation code to the font library as the new helper font_data_rotate(). The code can rotate in steps of 90°. For completeness, it also copies the glyph data for multiples of 360°. Bring back the memset optimization. A memset to 0 again clears the whole glyph output buffer. Then use the internal rotation helpers on the cleared output. Fbcon's original implementation worked like this, but lost it during refactoring. Replace fbcon's font-rotation code with the new implementations. All that's left to do for fbcon is to maintain its internal fbcon state. v2: - fix typos Signed-off-by: Thomas Zimmermann Signed-off-by: Helge Deller

lib/fonts: Implement glyph rotation

2026-04-07T15:38:07+00:00

Move the glyph rotation helpers from fbcon to the font library. Wrap them behind clean interfaces. Also clear the output memory to zero. Previously, the implementation relied on the caller to do that. Go through the fbcon code and callers of the glyph-rotation helpers. In addition to the font rotation, there's also the cursor code, which uses the rotation helpers. The font-rotation relied on a single memset to zero for the whole font. This is now multiple memsets on each glyph. This will be sorted out when the font library also implements font rotation. Building glyph rotation in the font library still depends on CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y. If we get more users of the code, we can still add a dedicated Kconfig symbol to the font library. No changes have been made to the actual implementation of the rotate_*() and pattern_*() functions. These will be refactored as separate changes. v2: - fix typos Signed-off-by: Thomas Zimmermann Signed-off-by: Helge Deller

lib/fonts: Provide helpers for calculating glyph pitch and size

2026-04-07T15:38:07+00:00

Implement pitch and size calculation for a single font glyph in the new helpers font_glyph_pitch() and font_glyph_size(). Replace the instances where the calculations are open-coded. Note that in the case of fbcon console rotation, the parameters for a glyph's width and height might be reversed. This is intentional. v2: - fix typos in commit message Signed-off-by: Thomas Zimmermann Signed-off-by: Helge Deller

fbcon: Avoid OOB font access if console rotation fails

2026-04-07T15:38:06+00:00

Clear the font buffer if the reallocation during console rotation fails in fbcon_rotate_font(). The putcs implementations for the rotated buffer will return early in this case. See [1] for an example. Currently, fbcon_rotate_font() keeps the old buffer, which is too small for the rotated font. Printing to the rotated console with a high-enough character code will overflow the font buffer. v2: - fix typos in commit message Signed-off-by: Thomas Zimmermann Fixes: 6cc50e1c5b57 ("[PATCH] fbcon: Console Rotation - Add support to rotate font bitmap") Cc: stable@vger.kernel.org # v2.6.15+ Link: https://elixir.bootlin.com/linux/v6.19/source/drivers/video/fbdev/core/fbcon_ccw.c#L144 # [1] Signed-off-by: Helge Deller

fbcon: Streamline setting rotated/unrotated bitops

2025-09-19T08:04:06+00:00

Support for console rotation is somewhat bolted onto the helper fbcon_set_bitops() for unrotated displays. Update fbcon_set_bitops() with a switch statement that picks the correct settings helper for the current rotation. For unrotated consoles, set the bitops for in the new helper fbcon_set_bitops_ur(). Rename the other, existing helpers to match the common naming scheme. The old helper fbcon_set_rotate() is no longer used. Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Link: https://lore.kernel.org/r/20250909124616.143365-6-tzimmermann@suse.de

fbcon: Set rotate_font callback with related callbacks

2025-09-19T08:04:04+00:00

The field struct fbcon_par.rotate_font points to fbcon_rotate_font() if the console is rotated. Set the callback in the same place as the other callbacks. Prepares for declaring all fbcon callbacks in a dedicated struct type. If not rotated, fbcon_set_bitops() still clears the callback to NULL. Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Link: https://lore.kernel.org/r/20250909124616.143365-4-tzimmermann@suse.de

fbcon: Rename struct fbcon_ops to struct fbcon_par

2025-09-19T08:04:02+00:00

The type struct fbcon_ops contains fbcon state and callbacks. As the callbacks will be removed from struct fbcon_ops, rename the data type to struct fbcon_par. Also rename the variables from ops to par. The _par postfix ("private access registers") is used throughout the fbdev subsystem for per-driver state. The fbcon pointer within struct fb_info is also named fbcon_par. Hence, the new naming fits existing practice. v2: - rename struct fbcon_ops to struct fbcon_par - fix build for CONFIG_FB_TILEBITTING=n (kernel test robot) - fix indention Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Link: https://lore.kernel.org/r/20250909124616.143365-3-tzimmermann@suse.de

fbcon: Drop EXPORT_SYMBOL

2020-11-17T10:00:43+00:00

Every since commit 6104c37094e729f3d4ce65797002112735d49cd1 Author: Daniel Vetter Date: Tue Aug 1 17:32:07 2017 +0200 fbcon: Make fbcon a built-time depency for fbdev these are no longer distinct loadable modules, so exporting symbols is kinda pointless. Acked-by: Thomas Zimmermann Signed-off-by: Daniel Vetter Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Daniel Vetter Cc: Tetsuo Handa Cc: Helge Deller Cc: Peilin Ye Link: https://patchwork.freedesktop.org/patch/msgid/20201029101428.4058311-2-daniel.vetter@ffwll.ch

fbcon: Avoid using FNTCHARCNT() and hard-coded built-in font charcount

2020-11-16T15:33:12+00:00

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 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 Signed-off-by: Peilin Ye Reviewed-by: Greg Kroah-Hartman Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/e460a5780e54e3022661d5f09555144583b4cc59.1605169912.git.yepeilin.cs@gmail.com