linux/drivers/tty/vt
lianzhi chang fb09d0ac07 tty: Fix the keyboard led light display problem
Use the "ctrl+alt+Fn" key combination to switch the system from tty to
desktop or switch the system from desktop to tty. After the switch is
completed, it is found that the state of the keyboard lock is
inconsistent with the state of the keyboard Led light.The reasons are
as follows:

* The desktop environment (Xorg and other services) is bound to a tty
  (assuming it is tty1), and the kb->kbdmode attribute value of tty1
  will be set to VC_OFF. According to the current code logic, in the
  desktop environment, the values of ledstate and kb->ledflagstate
  of tty1 will not be modified anymore, so they are always 0.

* When switching between each tty, the final value of ledstate set by
  the previous tty is compared with the kb->ledflagstate value of the
  current tty to determine whether to set the state of the keyboard
  light. The process of switching between desktop and tty is also the
  process of switching between tty1 and other ttys. There are two
  situations:

  - (1) In the desktop environment, tty1 will not set the ledstate,
  which will cause when switching from the desktop to other ttys,
  if the desktop lights up the keyboard's led, after the switch is
  completed, the keyboard's led light will always be on;

  - (2) When switching from another tty to the desktop, this
  mechanism will trigger tty1 to set the led state. If other tty
  lights up the led of the keyboard before switching to the desktop,
  the led will be forcibly turned off. This situation should
  be avoided.

* The current patch is to solve these problems: When VT is switched,
  the keyboard led needs to be set once.Ensure that after the
  switch is completed, the state of the keyboard LED is consistent
  with the state of the keyboard lock.

Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: lianzhi chang <changlianzhi@uniontech.com>
Link: https://lore.kernel.org/r/20211215125125.10554-1-changlianzhi@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-21 09:19:14 +01:00
..
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
conmakehash.c tty: vt: move conmakehash to drivers/tty/vt/ from scripts/ 2019-12-17 14:42:46 +01:00
consolemap.c vt/consolemap: do font sum unsigned 2021-01-07 16:17:31 +01:00
cp437.uni
defkeymap.c_shipped vt: keyboard, defkeymap.c_shipped, approach the unicode table 2021-01-07 16:17:31 +01:00
defkeymap.map
keyboard.c tty: Fix the keyboard led light display problem 2021-12-21 09:19:14 +01:00
Makefile kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
selection.c tty: vt: selection: Correct misspelled function sel_loadlut() 2021-05-20 17:05:33 +02:00
vc_screen.c Revert "vc_screen: extract vcs_read_buf_header" 2020-08-24 19:51:56 +02:00
vt_ioctl.c vt_kdsetmode: extend console locking 2021-08-30 08:55:18 -07:00
vt.c tty: drivers/tty/, stop using tty_schedule_flip() 2021-11-25 18:35:23 +01:00