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authorJoel Fernandes <joelagnelf@nvidia.com>2026-07-18 13:15:36 -0400
committerPaul E. McKenney <paulmck@kernel.org>2026-07-23 10:39:57 -0700
commit34ff636f322c6d5e4f0a52338fa63a7dff09a495 (patch)
tree7629759c1ec7148b95bc8ab3080df20a5ecd2273 /Documentation/driver-api/frame-buffer.rst
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scftorture: Count single_rpc offline failures in statistics outputgrafted
scf_torture_stats_print() aggregates each invoker thread's counters into a local scf_statistics structure before printing, but the n_single_rpc_ofl field is missing from the aggregation loop. As a result, the "single_rpc_ofl" value printed in the statistics line is always zero, even when smp_call_function_single() invocations for the RPC test have failed due to offline CPUs and been counted by the invoker threads. Add the missing accumulation so that the printed value reflects the actual counts. Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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+Frame Buffer Library
+====================
+
+The frame buffer drivers depend heavily on four data structures. These
+structures are declared in include/linux/fb.h. They are fb_info,
+fb_var_screeninfo, fb_fix_screeninfo and fb_monospecs. The last
+three can be made available to and from userland.
+
+fb_info defines the current state of a particular video card. Inside
+fb_info, there exists a fb_ops structure which is a collection of
+needed functions to make fbdev and fbcon work. fb_info is only visible
+to the kernel.
+
+fb_var_screeninfo is used to describe the features of a video card
+that are user defined. With fb_var_screeninfo, things such as depth
+and the resolution may be defined.
+
+The next structure is fb_fix_screeninfo. This defines the properties
+of a card that are created when a mode is set and can't be changed
+otherwise. A good example of this is the start of the frame buffer
+memory. This "locks" the address of the frame buffer memory, so that it
+cannot be changed or moved.
+
+The last structure is fb_monospecs. In the old API, there was little
+importance for fb_monospecs. This allowed for forbidden things such as
+setting a mode of 800x600 on a fix frequency monitor. With the new API,
+fb_monospecs prevents such things, and if used correctly, can prevent a
+monitor from being cooked. fb_monospecs will not be useful until
+kernels 2.5.x.
+
+Frame Buffer Memory
+-------------------
+
+.. kernel-doc:: drivers/video/fbdev/core/fbmem.c
+ :export:
+
+Frame Buffer Colormap
+---------------------
+
+.. kernel-doc:: drivers/video/fbdev/core/fbcmap.c
+ :export:
+
+Frame Buffer Video Mode Database
+--------------------------------
+
+.. kernel-doc:: drivers/video/fbdev/core/modedb.c
+ :internal:
+
+.. kernel-doc:: drivers/video/fbdev/core/modedb.c
+ :export:
+
+Frame Buffer Macintosh Video Mode Database
+------------------------------------------
+
+.. kernel-doc:: drivers/video/fbdev/macmodes.c
+ :export:
+
+Frame Buffer Fonts
+------------------
+
+Refer to the file lib/fonts/fonts.c for more information.
+