user/sven/linux.git/include/linux/console.h, branch v5.8.11

Merge branch 'for-5.8' into for-linus

2020-06-01T08:15:16Z

Merge branch 'for-5.7-console-exit' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk into tty-next

2020-03-17T14:26:43Z

We need the console patches in here as well for futher work from Andy. * 'for-5.7-console-exit' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: console: Introduce ->exit() callback console: Don't notify user space when unregister non-listed console console: Avoid positive return code from unregister_console() console: Drop misleading comment console: Use for_each_console() helper in unregister_console() console: Drop double check for console_drivers being non-NULL console: Don't perform test for CON_BRL flag Signed-off-by: Greg Kroah-Hartman

printk: Correctly set CON_CONSDEV even when preferred console was not registered

2020-02-18T08:35:24Z

CON_CONSDEV flag was historically used to put/keep the preferred console first in console_drivers list. Where the preferred console is the last on the command line. The ordering is important only when opening /dev/console: + tty_kopen() + tty_lookup_driver() + console_device() The flag was originally an implementation detail. But it was later made accessible from userspace via /proc/consoles. It was used, for example, by the tool "showconsole" to show the real tty accessible via /dev/console, see https://github.com/bitstreamout/showconsole Now, the current code sets CON_CONSDEV only for the preferred console or when a fallback console is added. The flag is not set when the preferred console is defined on the command line but it is not registered from some reasons. Simple solution is to set CON_CONSDEV flag for the first registered console. It will work most of the time because: + Most real consoles have console->device defined. + Boot consoles are removed in printk_late_init(). + unregister_console() moves CON_CONSDEV flag to the next console. Clean solution would require checking con->device when the preferred console is registered and in unregister_console(). Conclusion: Use the simple solution for now. It is better than the current state and good enough. The clean solution is not worth it. It would complicate the already complicated code without too much gain. Instead the code would deserve a complete rewrite. Link: https://lore.kernel.org/r/20200213095133.23176-4-pmladek@suse.com Signed-off-by: Benjamin Herrenschmidt [pmladek@suse.com: Correct reasoning in the commit message, comment update.] Reviewed-by: Petr Mladek Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek

console: Introduce ->exit() callback

2020-02-11T09:44:22Z

Some consoles might require special operations on unregistering. For instance, serial console, when registered in the kernel, keeps power on for entire time, until it gets unregistered. Example of use: ->setup(console): pm_runtime_get(...); ->exit(console): pm_runtime_put(...); For such cases to have a balance we would provide ->exit() callback. Link: http://lkml.kernel.org/r/20200203133130.11591-7-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt Signed-off-by: Andy Shevchenko Reviewed-by: Sergey Senozhatsky Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek

sparc/console: kill off obsolete declarations

2020-01-21T12:28:24Z

commit 09d3f3f0e02c ("sparc: Kill PROM console driver.") missed removing the declarations of the deleted prom_con structure and prom_con_init function from console.h. Kill them off now. Signed-off-by: Arvind Sankar Signed-off-by: David S. Miller

panic: add an option to replay all the printk message in buffer

2019-05-18T22:52:26Z

Currently on panic, kernel will lower the loglevel and print out pending printk msg only with console_flush_on_panic(). Add an option for users to configure the "panic_print" to replay all dmesg in buffer, some of which they may have never seen due to the loglevel setting, which will help panic debugging . [feng.tang@intel.com: keep the original console_flush_on_panic() inside panic()] Link: http://lkml.kernel.org/r/1556199137-14163-1-git-send-email-feng.tang@intel.com [feng.tang@intel.com: use logbuf lock to protect the console log index] Link: http://lkml.kernel.org/r/1556269868-22654-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1556095872-36838-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang Reviewed-by: Petr Mladek Cc: Aaro Koskinen Cc: Petr Mladek Cc: Steven Rostedt Cc: Sergey Senozhatsky Cc: Kees Cook Cc: Borislav Petkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

console: Replace #if 0 with atomic var 'ignore_console_lock_warning'

2018-07-31T11:06:57Z

The macro WARN_CONSOLE_UNLOCKED prints a warning when a thread enters the console's critical section without having acquired the console lock. The console lock can be ignored when debugging the console using printk, but this makes WARN_CONSOLE_UNLOCKED generate unnecessary warnings. The variable ignore_console_lock_warning temporarily disables WARN_CONSOLE_UNLOCKED. Developers interested in debugging the console's critical sections should increment it before entering the CS and decrement it after leaving the CS. Setting ignore_console_lock_warning is only for debugging. Regular operation should not manipulate it. Acknoledgements: This patch is based on an earlier version by Steven Rostedt. The use of atomic increment/decrement was suggested by Petr Mladek. Link: http://lkml.kernel.org/r/717e6337-e7a6-7a92-1c1b-8929a25696b5@suse.de Signed-off-by: Thomas Zimmermann Acked-by: Hans de Goede Acked-by: Petr Mladek Reviewed-by: Sergey Senozhatsky Cc: Steven Rostedt (VMware) Cc: Andrew Morton [b.zolnierkie: use ] Signed-off-by: Bartlomiej Zolnierkiewicz

console/fbcon: Add support for deferred console takeover

2018-06-28T13:20:30Z

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

console: Fill in struct consw argument names

2018-02-27T09:17:33Z

Reading the function declarations for the console callbacks lacks any hints as to what the arguments are. Instead of going and digging around in various implementations that may each only have a subset of the callbacks, name all the arguments in the declaration. This has no functional change. Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

console: move console_init() out of tty_io.c

2017-04-18T16:01:52Z

All the console driver handling code lives in printk.c. Move console_init() there as well so console support can still be used when the TTY code is configured out. No logical changes from this patch. Signed-off-by: Nicolas Pitre Signed-off-by: Greg Kroah-Hartman