diff options
| author | Sven Schnelle <svens@linux.ibm.com> | 2026-09-09 11:29:53 +0200 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-09-10 08:43:35 +0900 |
| commit | d22c3e0088e85be8131f7a9283f759cdbb20726d (patch) | |
| tree | 9668df2aa27b26f850d3ba5ba1287e443803675c /Documentation/fb/internals.rst | |
| download | linux-stable-d22c3e0088e85be8131f7a9283f759cdbb20726d.tar.gz linux-stable-d22c3e0088e85be8131f7a9283f759cdbb20726d.zip | |
selftests/ftrace: Fix unique symbol check in kprobe_non_uniq_symbol.tcgrafted
The current regex also matches symbols in modules, which makes the
test fail on s390 where name_show is present only once in the kernel,
but also multiple times in modules:
000001b1401cdc20 t name_show
000001b0c05e6c40 t name_show [mdev]
000001b0c0495f30 t name_show [i2c_core]
Fix this by changing the regular expression to only match the function
name.
Link: https://lore.kernel.org/all/20260909092954.2200558-1-svens@linux.ibm.com/
Fixes: 03b80ff8023a ("selftests/ftrace: Add new test case which checks non unique symbol")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'Documentation/fb/internals.rst')
| -rw-r--r-- | Documentation/fb/internals.rst | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/Documentation/fb/internals.rst b/Documentation/fb/internals.rst new file mode 100644 index 000000000..696b50aa7 --- /dev/null +++ b/Documentation/fb/internals.rst @@ -0,0 +1,86 @@ +============================= +Frame Buffer device internals +============================= + +This is a first start for some documentation about frame buffer device +internals. + +Authors: + +- Geert Uytterhoeven <geert@linux-m68k.org>, 21 July 1998 +- James Simmons <jsimmons@user.sf.net>, Nov 26 2002 + +-------------------------------------------------------------------------------- + +Structures used by the frame buffer device API +============================================== + +The following structures play a role in the game of frame buffer devices. They +are defined in <linux/fb.h>. + +1. Outside the kernel (user space) + + - struct fb_fix_screeninfo + + Device independent unchangeable information about a frame buffer device and + a specific video mode. This can be obtained using the FBIOGET_FSCREENINFO + ioctl. + + - struct fb_var_screeninfo + + Device independent changeable information about a frame buffer device and a + specific video mode. This can be obtained using the FBIOGET_VSCREENINFO + ioctl, and updated with the FBIOPUT_VSCREENINFO ioctl. If you want to pan + the screen only, you can use the FBIOPAN_DISPLAY ioctl. + + - struct fb_cmap + + Device independent colormap information. You can get and set the colormap + using the FBIOGETCMAP and FBIOPUTCMAP ioctls. + + +2. Inside the kernel + + - struct fb_info + + Generic information, API and low level information about a specific frame + buffer device instance (slot number, board address, ...). + + - struct `par` + + Device dependent information that uniquely defines the video mode for this + particular piece of hardware. + + +Visuals used by the frame buffer device API +=========================================== + + +Monochrome (FB_VISUAL_MONO01 and FB_VISUAL_MONO10) +-------------------------------------------------- +Each pixel is either black or white. + + +Pseudo color (FB_VISUAL_PSEUDOCOLOR and FB_VISUAL_STATIC_PSEUDOCOLOR) +--------------------------------------------------------------------- +The whole pixel value is fed through a programmable lookup table that has one +color (including red, green, and blue intensities) for each possible pixel +value, and that color is displayed. + + +True color (FB_VISUAL_TRUECOLOR) +-------------------------------- +The pixel value is broken up into red, green, and blue fields. + + +Direct color (FB_VISUAL_DIRECTCOLOR) +------------------------------------ +The pixel value is broken up into red, green, and blue fields, each of which +are looked up in separate red, green, and blue lookup tables. + + +Grayscale displays +------------------ +Grayscale and static grayscale are special variants of pseudo color and static +pseudo color, where the red, green and blue components are always equal to +each other. |
