linux-toradex.git/Documentation/fb, branch v4.19-rc5

Documentation/fb: corrections for fbcon.txt

2018-08-10T15:23:02+00:00

Fix grammar, spacing, indentation, and Kconfig menu locations
in fbcon.txt.

Signed-off-by: Randy Dunlap 
Cc: Antonino Daplas 
Cc: Geert Uytterhoeven 
Cc: Jonathan Corbet 
Signed-off-by: Bartlomiej Zolnierkiewicz

console/fbcon: Add support for deferred console takeover

2018-06-28T13:20:30+00:00

Currently fbcon claims fbdevs as soon as they are registered and takes over
the console as soon as the first fbdev gets registered.

This behavior is undesirable in cases where a smooth graphical bootup is
desired, in such cases we typically want the contents of the framebuffer
(typically a vendor logo) to stay in place as is.

The current solution for this problem (on embedded systems) is to not
enable fbcon.

This commit adds a new FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER config option,
which when enabled defers fbcon taking over the console from the dummy
console until the first text is displayed on the console. Together with the
"quiet" kernel commandline option, this allows fbcon to still be used
together with a smooth graphical bootup, having it take over the console as
soon as e.g. an error message is logged.

Note the choice to detect the first console output in the dummycon driver,
rather then handling this entirely inside the fbcon code, was made after
2 failed attempts to handle this entirely inside the fbcon code. The fbcon
code is woven quite tightly into the console code, making this to only
feasible option.

Reviewed-by: Daniel Vetter 
Signed-off-by: Hans de Goede 
Signed-off-by: Bartlomiej Zolnierkiewicz

documentation: fb: update list of available compiled-in fonts

2017-11-08T10:39:52+00:00

Update list of available compiled-in fonts in lib/fonts/:
add 6x10 and drop RomanLarge (which was reverted 12 years ago).

Also sort the list alphabetically.

Signed-off-by: Randy Dunlap 
Acked-by: Geert Uytterhoeven  # v1
Signed-off-by: Jonathan Corbet

fbcon: remove restriction on margin color

2017-09-04T14:00:49+00:00

This removes the restriction on the value range of the fbcon=margin:
parameter. The color value really depends on the driver being used.

Signed-off-by: David Lechner 
Cc: Geert Uytterhoeven 
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz

fbcon: add fbcon=margin: command line option

2017-08-18T17:56:40+00:00

This adds a new command line option to select the fbcon margin color.

The motivation for this is screens where black does not blend into the
physical surroundings of the screen. For example, using an LCD (not the
backlit kind), white text on a black background is hard to read, so
inverting the colors is preferred. However, when you do this, most of the
screen is filled with white but the margins are still filled with black.
This makes a big, black, backwards 'L' on the screen. By setting
fbcon=margin:7, the margins will be filled with white and the LCD looks as
expected.

Signed-off-by: David Lechner 
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz

efifb: allow user to disable write combined mapping.

2017-07-31T16:45:41+00:00

This patch allows the user to disable write combined mapping
of the efifb framebuffer console using an nowc option.

A customer noticed major slowdowns while logging to the console
with write combining enabled, on other tasks running on the same
CPU. (10x or greater slow down on all other cores on the same CPU
as is doing the logging).

I reproduced this on a machine with dual CPUs.
Intel(R) Xeon(R) CPU E5-2609 v3 @ 1.90GHz (6 core)

I wrote a test that just mmaps the pci bar and writes to it in
a loop, while this was running in the background one a single
core with (taskset -c 1), building a kernel up to init/version.o
(taskset -c 8) went from 13s to 133s or so. I've yet to explain
why this occurs or what is going wrong I haven't managed to find
a perf command that in any way gives insight into this.

    11,885,070,715      instructions              #    1.39  insns per cycle
vs
    12,082,592,342      instructions              #    0.13  insns per cycle

is the only thing I've spotted of interest, I've tried at least:
dTLB-stores,dTLB-store-misses,L1-dcache-stores,LLC-store,LLC-store-misses,LLC-load-misses,LLC-loads,\mem-loads,mem-stores,iTLB-loads,iTLB-load-misses,cache-references,cache-misses

For now it seems at least a good idea to allow a user to disable write
combining if they see this until we can figure it out.

Note also most users get a real framebuffer driver loaded when kms
kicks in, it just happens on these machines the kernel didn't support
the gpu specific driver.

Signed-off-by: Dave Airlie 
Acked-by: Peter Jones 
Cc: Andy Lutomirski 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Signed-off-by: Bartlomiej Zolnierkiewicz

docs: update old references for DocBook from the documentation

2017-05-16T11:44:19+00:00

DocBook is mentioned several times at the documentation. Update
the obsolete references from it at the DocBook.

Acked-by: SeongJae Park 
Signed-off-by: Mauro Carvalho Chehab

Documentation: fb: fix spelling mistakes

2016-05-10T09:05:27+00:00

Signed-off-by: Eric Engestrom 
Signed-off-by: Tomi Valkeinen

Documentation/fb: add documentation for sm712fb

2015-08-07T22:05:01+00:00

Create the documentation for SM712. Mention all the supported modes and
how to use.

Signed-off-by: Sudip Mukherjee 
Signed-off-by: Greg Kroah-Hartman

doc: spelling error changes

2014-05-05T13:32:05+00:00

Fixed multiple spelling errors.

Acked-by: Randy Dunlap 
Signed-off-by: Carlos E. Garcia 
Signed-off-by: Jiri Kosina