From bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 20 Sep 2026 08:15:23 -0700
Subject: Merge tag 'locking-urgent-2026-09-20' of
 git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull futex fix from Ingo Molnar:

 - Also allocate a default private futex hash on vfork() as well, to
   avoid races with (private) futex waiters (Peter Zijlstra)

* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Also allocate private hash on vfork()
---
 Documentation/fb/internals.rst | 86 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/fb/internals.rst

(limited to 'Documentation/fb/internals.rst')

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.
-- 
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