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* tty: add missing MODULE_DESCRIPTION() macrosJeff Johnson2024-06-241-0/+1
| | | | | | | | | | | | | | | | | | | | make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/8250/8250_base.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/8250/8250_pxa.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/8250/serial_cs.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/esp32_uart.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/esp32_acm.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/owl-uart.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/n_hdlc.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/n_gsm.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/ttynull.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/goldfish.o Add all missing invocations of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: make tty_operations::write()'s count size_tJiri Slaby (SUSE)2023-08-111-1/+2
| | | | | | | | | Unify with the rest of the code. Use size_t for counts and ssize_t for retval. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: propagate u8 data to tty_operations::write()Jiri Slaby (SUSE)2023-08-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Data are now typed as u8. Propagate this change to tty_operations::write(). Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Matt Turner <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Anton Ivanov <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Chris Zankel <[email protected]> Cc: Max Filippov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Vaibhav Gupta <[email protected]> Cc: Jens Taprogge <[email protected]> Cc: Karsten Keil <[email protected]> Cc: Scott Branden <[email protected]> Cc: Ulf Hansson <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Paolo Abeni <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: David Lin <[email protected]> Cc: Johan Hovold <[email protected]> Cc: Alex Elder <[email protected]> Cc: Laurentiu Tudor <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: David Sterba <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Pengutronix Kernel Team <[email protected]> Cc: Fabio Estevam <[email protected]> Cc: NXP Linux Team <[email protected]> Cc: Arnaud Pouliquen <[email protected]> Cc: Oliver Neukum <[email protected]> Cc: Mathias Nyman <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: drop put_tty_driverJiri Slaby2021-07-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | put_tty_driver() is an alias for tty_driver_kref_put(). There is no need for two exported identical functions, therefore switch all users of old put_tty_driver() to new tty_driver_kref_put() and remove the former for good. Cc: Richard Henderson <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Matt Turner <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Anton Ivanov <[email protected]> Cc: Chris Zankel <[email protected]> Cc: Max Filippov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Samuel Iglesias Gonsalvez <[email protected]> Cc: Jens Taprogge <[email protected]> Cc: Karsten Keil <[email protected]> Cc: Scott Branden <[email protected]> Cc: Ulf Hansson <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: David Lin <[email protected]> Cc: Johan Hovold <[email protected]> Cc: Alex Elder <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Laurentiu Tudor <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: David Sterba <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Pengutronix Kernel Team <[email protected]> Cc: Fabio Estevam <[email protected]> Cc: NXP Linux Team <[email protected]> Cc: Oliver Neukum <[email protected]> Cc: Felipe Balbi <[email protected]> Cc: Mathias Nyman <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Acked-by: Alex Elder <[email protected]> Acked-by: Christian Borntraeger <[email protected]> Acked-by: Max Filippov <[email protected]> Acked-by: David Sterba <[email protected]> Acked-by: Samuel Iglesias Gonsálvez <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: make tty_operations::write_room return uintJiri Slaby2021-05-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Line disciplines expect a positive value or zero returned from tty->ops->write_room (invoked by tty_write_room). So make this assumption explicit by using unsigned int as a return value. Both of tty->ops->write_room and tty_write_room. Signed-off-by: Jiri Slaby <[email protected]> Acked-by: Laurentiu Tudor <[email protected]> Acked-by: Alex Elder <[email protected]> Acked-by: Max Filippov <[email protected]> # xtensa Acked-by: David Sterba <[email protected]> Acked-By: Anton Ivanov <[email protected]> Acked-by: Geert Uytterhoeven <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Matt Turner <[email protected]> Cc: "James E.J. Bottomley" <[email protected]> Cc: Helge Deller <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Chris Zankel <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Samuel Iglesias Gonsalvez <[email protected]> Cc: Jens Taprogge <[email protected]> Cc: Karsten Keil <[email protected]> Cc: Scott Branden <[email protected]> Cc: Ulf Hansson <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: David Lin <[email protected]> Cc: Johan Hovold <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Oliver Neukum <[email protected]> Cc: Felipe Balbi <[email protected]> Cc: Mathias Nyman <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* Revert "init/console: Use ttynull as a fallback when there is no console"Petr Mladek2021-01-081-18/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 757055ae8dedf5333af17b3b5b4b70ba9bc9da4e. The commit caused that ttynull was used as the default console on several systems[1][2][3]. As a result, the console was blank even when a better alternative existed. It happened when there was no console configured on the command line and ttynull_init() was the first initcall calling register_console(). Or it happened when /dev/ did not exist when console_on_rootfs() was called. It was not able to open /dev/console even though a console driver was registered. It tried to add ttynull console but it obviously did not help. But ttynull became the preferred console and was used by /dev/console when it was available later. The commit tried to fix a historical problem that have been there for ages. The primary motivation was the commit 3cffa06aeef7ece30f6 ("printk/console: Allow to disable console output by using console="" or console=null"). It provided a clean solution for a workaround that was widely used and worked only by chance. This revert causes that the console="" or console=null command line options will again work only by chance. These options will cause that a particular console will be preferred and the default (tty) ones will not get enabled. There will be no console registered at all. As a result there won't be stdin, stdout, and stderr for the init process. But it worked exactly this way even before. The proper solution has to fulfill many conditions: + Register ttynull only when explicitly required or as the ultimate fallback. + ttynull should get associated with /dev/console but it must not become preferred console when used as a fallback. Especially, it must still be possible to replace it by a better console later. Such a change requires clean up of the register_console() code. Otherwise, it would be even harder to follow. Especially, the use of has_preferred_console and CON_CONSDEV flag is tricky. The clean up is risky. The ordering of consoles is not well defined. And any changes tend to break existing user settings. Do the revert at the least risky solution for now. [1] https://lore.kernel.org/linux-kselftest/[email protected]/ [2] https://lore.kernel.org/lkml/[email protected]/ [3] https://patchwork.ozlabs.org/project/linux-um/patch/[email protected]/ Reported-by: Andy Shevchenko <[email protected]> Reported-by: Vineet Gupta <[email protected]> Reported-by: Thomas Meyer <[email protected]> Signed-off-by: Petr Mladek <[email protected]> Acked-by: Greg Kroah-Hartman <[email protected]> Acked-by: Sergey Senozhatsky <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
* init/console: Use ttynull as a fallback when there is no consolePetr Mladek2020-11-201-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | stdin, stdout, and stderr standard I/O stream are created for the init process. They are not available when there is no console registered for /dev/console. It might lead to a crash when the init process tries to use them, see the commit 48021f98130880dd742 ("printk: handle blank console arguments passed in."). Normally, ttySX and ttyX consoles are used as a fallback when no consoles are defined via the command line, device tree, or SPCR. But there will be no console registered when an invalid console name is configured or when the configured consoles do not exist on the system. Users even try to avoid the console intentionally, for example, by using console="" or console=null. It is used on production systems where the serial port or terminal are not visible to users. Pushing messages to these consoles would just unnecessary slowdown the system. Make sure that stdin, stdout, stderr, and /dev/console are always available by a fallback to the existing ttynull driver. It has been implemented for exactly this purpose but it was used only when explicitly configured. Reviewed-by: Greg Kroah-Hartman <[email protected]> Reviewed-by: Guenter Roeck <[email protected]> Tested-by: Guenter Roeck <[email protected]> Acked-by: Sergey Senozhatsky <[email protected]> Signed-off-by: Petr Mladek <[email protected]> Link: https://lore.kernel.org/r/[email protected]
* tty: Add NULL TTY driverVincent Whitchurch2019-04-161-0/+109
If no console driver is enabled (or if a non-present driver is selected with something like console=null in an attempt to disable the console), opening /dev/console errors out, and init scripts and other userspace code that relies on the existence of a console will fail. Symlinking /dev/null to /dev/console does not solve the problem since /dev/null does not behave like a real TTY. To just provide a dummy console to userspace when no console driver is available or desired, add a ttynull driver which simply discards all writes. It can be chosen on the command line in the standard way, i.e. with console=ttynull. Signed-off-by: Vincent Whitchurch <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>