linux.git/drivers/tty/Makefile, branch v6.12.80

tty: add rpmsg driver

2021-10-21T10:35:35+00:00

This driver exposes a standard TTY interface on top of the rpmsg
framework through a rpmsg service.

This driver supports multi-instances, offering a /dev/ttyRPMSGx entry
per rpmsg endpoint.

Reviewed-by: Mathieu Poirier 
Signed-off-by: Arnaud Pouliquen 
Link: https://lore.kernel.org/r/20211015094701.5732-3-arnaud.pouliquen@foss.st.com
Signed-off-by: Greg Kroah-Hartman

tty: remove broken r3964 line discipline

2021-05-13T14:57:15+00:00

Noone stepped up in the past two years since it was marked as BROKEN by
commit c7084edc3f6d (tty: mark Siemens R3964 line discipline as BROKEN).
Remove the line discipline for good.

Three remarks:
* we remove also the uapi header (as noone is able to use that interface
  anyway)
* we do *not* remove the N_R3964 constant definition from tty.h, so it
  remains reserved.
* in_interrupt() check is now removed from vt's con_put_char. Noone else
  calls tty_operations::put_char from interrupt context.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210505091928.22010-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: rocket, remove the driver

2021-03-10T08:34:06+00:00

While the driver is still marked as maintained in MAINTAINERS, Comtrol
does not really care about this ancient driver. They are still
manufacturing serial devices, but those are controlled only by
out-of-tree drivers.

Comtrol didn't answer my pings, so this driver is apparently
unmaintained.  Aside from that, the driver was untouched for years, only
whole-tree changes happened during the past years. The driver needs much
more care, so drop it for now. If someone steps up to reintroduce it,
they need to clean it up first.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210302062214.29627-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: isicom, remove this orphan

2021-03-10T08:34:06+00:00

The Isicom driver was orphaned by commit d86b3001a1a6 (MAINTAINERS:
orphan isicom) 10 years ago. Noone stepped up to take care of them and
to fix all the issues the driver has.

So it's time to drop the driver with all its traces.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210302062214.29627-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: cyclades, remove this orphan

2021-03-10T08:34:06+00:00

The Cyclades driver was orphaned by commit d459883e6c54 (MAINTAINERS:
remove two dead e-mail) 13 years ago. Noone stepped up to take care of
them and to fix all the issues the driver has.

On the top of that, there is no way to obtain the firmware for Z cards
from the vendor as cyclades.com ceased to exist.

So it's time to drop the driver with all its traces.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210302062214.29627-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

misc: pti: Remove driver for deprecated platform

2021-01-27T12:35:01+00:00

Intel Moorestown and Medfield are quite old Intel Atom based
32-bit platforms, which were in limited use in some Android phones,
tablets and consumer electronics more than eight years ago.

There are no bugs or problems ever reported outside from Intel
for breaking any of that platforms for years. It seems no real
users exists who run more or less fresh kernel on it. The commit
05f4434bc130 ("ASoC: Intel: remove mfld_machine") also in align
with this theory.

Due to above and to reduce a burden of supporting outdated drivers
we remove the support of outdated platforms completely.

Cc: Alexander Shishkin 
Acked-by: Linus Walleij 
Acked-by: Arnd Bergmann 
Acked-by: Alexander Shishkin 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20210122114358.39299-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

Revert "init/console: Use ttynull as a fallback when there is no console"

2021-01-08T19:02:18+00:00

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/20201221144302.GR4077@smile.fi.intel.com/
[2] https://lore.kernel.org/lkml/d2a3b3c0-e548-7dd1-730f-59bc5c04e191@synopsys.com/
[3] https://patchwork.ozlabs.org/project/linux-um/patch/20210105120128.10854-1-thomas@m3y3r.de/

Reported-by: Andy Shevchenko
Reported-by: Vineet Gupta
Reported-by: Thomas Meyer
Signed-off-by: Petr Mladek
Acked-by: Greg Kroah-Hartman
Acked-by: Sergey Senozhatsky
Signed-off-by: Linus Torvalds

Merge tag 'printk-for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2020-12-16T18:45:11+00:00

Pull printk updates from Petr Mladek:

 - Finally allow parallel writes and reads into/from the lockless
   ringbuffer. But it is not a complete solution. Readers are still
   serialized against each other. And nested writes are still prevented
   by printk_safe per-CPU buffers.

 - Use ttynull as the ultimate fallback for /dev/console.

 - Officially allow disabling console output by using console="" or
   console=null

 - A few code cleanups

* tag 'printk-for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: remove logbuf_lock writer-protection of ringbuffer
  printk: inline log_output(),log_store() in vprintk_store()
  printk: remove obsolete dead assignment
  printk/console: Allow to disable console output by using console="" or console=null
  init/console: Use ttynull as a fallback when there is no console
  printk: ringbuffer: Reference text_data_ring directly in callees.

init/console: Use ttynull as a fallback when there is no console

2020-11-20T11:23:50+00:00

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 
Reviewed-by: Guenter Roeck 
Tested-by: Guenter Roeck 
Acked-by: Sergey Senozhatsky 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20201111135450.11214-2-pmladek@suse.com

tty: Remove redundant synclinkmp driver

2020-11-06T16:10:58+00:00

A note from the vendor:

 "The hardware used with synclink.c and synclinkmp.c has not been
  manufactured for 15 years and was low volume. The chances of either
  driver still being in use is very low. Not even Microgate (me) has
  the ability to test either anymore (no hardware). I don’t know the
  policy about driver removal, but I think both could be removed
  without upsetting anyone."

Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones 
Link: https://lore.kernel.org/r/20201105123357.708813-3-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman