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TTY:console: update document console.txt

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Update Documentatin/console/console.txt to
reflect the following changes:

take_over_console|register_con_driver|unregister_con_driver|bind_con_driver
had gone, they had been replace by the new caller hold console lock version,
do_take_over_console|do_register_con_driver|do_unregister_con_driver|do_bind_con_driver.

This patch also fix a place include wrong description about give_up_console.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Wang YanQing 2013-05-21 23:29:11 +08:00 committed by Greg Kroah-Hartman
parent 155957f56c
commit 6b5f146535
1 changed files with 14 additions and 14 deletions
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28
Documentation/console/console.txt
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@ -12,20 +12,20 @@ The second type has to be explicitly loaded and unloaded. This will be called
any time with each driver sharing the console with other drivers including
the system driver. However, modular drivers cannot take over the console
that is currently occupied by another modular driver. (Exception: Drivers that
call take_over_console() will succeed in the takeover regardless of the type
call do_take_over_console() will succeed in the takeover regardless of the type
of driver occupying the consoles.) They can only take over the console that is
occupied by the system driver. In the same token, if the modular driver is
released by the console, the system driver will take over.
Modular drivers, from the programmer's point of view, has to call:
take_over_console() - load and bind driver to console layer
give_up_console() - unbind and unload driver
do_take_over_console() - load and bind driver to console layer
give_up_console() - unload driver, it will only work if driver is fully unbond
In newer kernels, the following are also available:
register_con_driver()
unregister_con_driver()
do_register_con_driver()
do_unregister_con_driver()
If sysfs is enabled, the contents of /sys/class/vtconsole can be
examined. This shows the console backends currently registered by the
@ -94,12 +94,12 @@ for more details).
Notes for developers:
=====================
take_over_console() is now broken up into:
do_take_over_console() is now broken up into:
register_con_driver()
bind_con_driver() - private function
do_register_con_driver()
do_bind_con_driver() - private function
give_up_console() is a wrapper to unregister_con_driver(), and a driver must
give_up_console() is a wrapper to do_unregister_con_driver(), and a driver must
be fully unbound for this call to succeed. con_is_bound() will check if the
driver is bound or not.
@ -109,10 +109,10 @@ Guidelines for console driver writers:
In order for binding to and unbinding from the console to properly work,
console drivers must follow these guidelines:
1. All drivers, except system drivers, must call either register_con_driver()
or take_over_console(). register_con_driver() will just add the driver to
1. All drivers, except system drivers, must call either do_register_con_driver()
or do_take_over_console(). do_register_con_driver() will just add the driver to
the console's internal list. It won't take over the
console. take_over_console(), as it name implies, will also take over (or
console. do_take_over_console(), as it name implies, will also take over (or
bind to) the console.
2. All resources allocated during con->con_init() must be released in
@ -128,10 +128,10 @@ console drivers must follow these guidelines:
rebind the driver to the console arrives.
4. Upon exit of the driver, ensure that the driver is totally unbound. If the
condition is satisfied, then the driver must call unregister_con_driver()
condition is satisfied, then the driver must call do_unregister_con_driver()
or give_up_console().
5. unregister_con_driver() can also be called on conditions which make it
5. do_unregister_con_driver() can also be called on conditions which make it
impossible for the driver to service console requests. This can happen
with the framebuffer console that suddenly lost all of its drivers.