tty: make tty_operations::write()'s count size_t

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

tty: make tty_operations::write()'s count size_t

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]>

show more ...

tty: propagate u8 data to tty_operations::write()

Data are now typed as u8. Propagate this change to
tty_operations::write().

Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]>
Cc: Richard H

tty: propagate u8 data to tty_operations::write()

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]>

show more ...

tty: drop put_tty_driver

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_

tty: drop put_tty_driver

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]>

show more ...

tty: stop using alloc_tty_driver

alloc_tty_driver was deprecated by tty_alloc_driver in commit
7f0bc6a68ed9 (TTY: pass flags to alloc_tty_driver) in 2012.

I never got into eliminating alloc_tty_dri

tty: stop using alloc_tty_driver

alloc_tty_driver was deprecated by tty_alloc_driver in commit
7f0bc6a68ed9 (TTY: pass flags to alloc_tty_driver) in 2012.

I never got into eliminating alloc_tty_driver until now. So we still
have two functions for allocating drivers which might be confusing. So
get rid of alloc_tty_driver uses to eliminate it for good in the next
patch.

Note we need to switch return value checking as tty_alloc_driver uses
ERR_PTR. And flags are now a parameter of tty_alloc_driver.

Cc: Richard Henderson <[email protected]>(odd fixer:ALPHA PORT)
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Geert Uytterhoeven <[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: Anton Ivanov <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Samuel Iglesias Gonsalvez <[email protected]>
Cc: Jens Taprogge <[email protected]>
Cc: Karsten Keil <[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: 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: Oliver Neukum <[email protected]>
Cc: Felipe Balbi <[email protected]>
Cc: Johan Hovold <[email protected]>
Cc: Marcel Holtmann <[email protected]>
Cc: Johan Hedberg <[email protected]>
Cc: Luiz Augusto von Dentz <[email protected]>
Acked-by: Samuel Iglesias Gonsálvez <[email protected]>
Acked-by: Max Filippov <[email protected]>
Acked-by: David Sterba <[email protected]>
Acked-by: Christian Borntraeger <[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]>

show more ...

ipwireless: remove unused ipw_tty::closing

It's only set, but never read because commit 01261cb94318 ("tty:
ipwireless: Remove tty->closing abort from ipw_open()") removed last use
of tty::closing.

ipwireless: remove unused ipw_tty::closing

It's only set, but never read because commit 01261cb94318 ("tty:
ipwireless: Remove tty->closing abort from ipw_open()") removed last use
of tty::closing.

Cc: Jiri Kosina <[email protected]>
Cc: David Sterba <[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]>

show more ...

tty: make tty_operations::chars_in_buffer return uint

tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsig

tty: make tty_operations::chars_in_buffer return uint

tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsigned int.

Signed-off-by: Jiri Slaby <[email protected]>
Acked-By: Anton Ivanov <[email protected]>
Acked-by: David Sterba <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Samuel Iglesias Gonsalvez <[email protected]>
Cc: Jens Taprogge <[email protected]>
Cc: Karsten Keil <[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 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]>

show more ...

tty: make tty_operations::write_room return uint

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

tty: make tty_operations::write_room return uint

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]>

show more ...

tty: make everyone's write_room return >= 0

The tty line disciplines don't expect tty_operations::write_room to
return negative values. Fix the five drivers which violate this.

Signed-off-by: Jiri

tty: make everyone's write_room return >= 0

The tty line disciplines don't expect tty_operations::write_room to
return negative values. Fix the five drivers which violate this.

Signed-off-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

tty: do not check tty_unregister_driver's return value

These drivers check tty_unregister_driver return value. But they don't
handle a failure correctly (they free the driver in any case). So stop
c

tty: do not check tty_unregister_driver's return value

These drivers check tty_unregister_driver return value. But they don't
handle a failure correctly (they free the driver in any case). So stop
checking tty_unregister_driver return value and remove also the prints.

In the next patch, tty_unregister_driver's return type will be switched
to void.

Cc: Chris Zankel <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: [email protected]
Cc: Jiri Kosina <[email protected]>
Cc: David Sterba <[email protected]>
Reviewed-by: Max Filippov <[email protected]>
Acked-by: David Sterba <[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]>

show more ...

tty_port: drop last traces of low_latency

The main purpose of tty_port::low_latency was removed in commit
a9c3f68f3cd8 (tty: Fix low_latency BUG) back in 2014. It was left in
place for drivers as an

tty_port: drop last traces of low_latency

The main purpose of tty_port::low_latency was removed in commit
a9c3f68f3cd8 (tty: Fix low_latency BUG) back in 2014. It was left in
place for drivers as an optional tune knob. But only one driver has been
using it until the previous commit. So remove this misconcept
completely, given there are no users.

Signed-off-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

tty: ipwireless: fix error handling

ipwireless_send_packet() can only return 0 on success and -ENOMEM on
error, the caller should check non zero for error condition

Signed-off-by: Tong Zhang <ztong

tty: ipwireless: fix error handling

ipwireless_send_packet() can only return 0 on success and -ENOMEM on
error, the caller should check non zero for error condition

Signed-off-by: Tong Zhang <[email protected]>
Acked-by: David Sterba <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

ipwireless: switch to ->[sg]et_serial()

Acked-by: David Sterba <[email protected]>
Signed-off-by: Al Viro <[email protected]>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

tty: ipwireless, cleanup TIOCGSERIAL

In ipwireless_get_serial_info, struct serial_struct is memset to 0 and
then some members set to 0 explicitly.

Remove the latter as it is obviously superfluous.

tty: ipwireless, cleanup TIOCGSERIAL

In ipwireless_get_serial_info, struct serial_struct is memset to 0 and
then some members set to 0 explicitly.

Remove the latter as it is obviously superfluous.

And remove the retinfo check against NULL. copy_to_user will take care
of that.

Part of hub6 cleanup series.

Signed-off-by: Jiri Slaby <[email protected]>
Cc: Jiri Kosina <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

tty: ipwireless: Remove tty->closing abort from ipw_open()

tty->closing cannot be set on ipw_open() because the ipwireless tty
driver does not call any functions that set tty->closing.

CC: Jiri Kos

tty: ipwireless: Remove tty->closing abort from ipw_open()

tty->closing cannot be set on ipw_open() because the ipwireless tty
driver does not call any functions that set tty->closing.

CC: Jiri Kosina <[email protected]>
Signed-off-by: Peter Hurley <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

tty: Fix low_latency BUG

The user-settable knob, low_latency, has been the source of
several BUG reports which stem from flush_to_ldisc() running
in interrupt context. Since 3.12, which added severa

tty: Fix low_latency BUG

The user-settable knob, low_latency, has been the source of
several BUG reports which stem from flush_to_ldisc() running
in interrupt context. Since 3.12, which added several sleeping
locks (termios_rwsem and buf->lock) to the input processing path,
the frequency of these BUG reports has increased.

Note that changes in 3.12 did not introduce this regression;
sleeping locks were first added to the input processing path
with the removal of the BKL from N_TTY in commit
a88a69c91256418c5907c2f1f8a0ec0a36f9e6cc,
'n_tty: Fix loss of echoed characters and remove bkl from n_tty'
and later in commit 38db89799bdf11625a831c5af33938dcb11908b6,
'tty: throttling race fix'. Since those changes, executing
flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe.

However, since most devices do not validate if the low_latency
setting is appropriate for the context (process or interrupt) in
which they receive data, some reports are due to misconfiguration.
Further, serial dma devices for which dma fails, resort to
interrupt receiving as a backup without resetting low_latency.

Historically, low_latency was used to force wake-up the reading
process rather than wait for the next scheduler tick. The
effect was to trim multiple milliseconds of latency from
when the process would receive new data.

Recent tests [1] have shown that the reading process now receives
data with only 10's of microseconds latency without low_latency set.

Remove the low_latency rx steering from tty_flip_buffer_push();
however, leave the knob as an optional hint to drivers that can
tune their rx fifos and such like. Cleanup stale code comments
regarding low_latency.

[1] https://lkml.org/lkml/2014/2/20/434

"Yay.. thats an annoying historical pain in the butt gone."
-- Alan Cox

Reported-by: Beat Bolli <[email protected]>
Reported-by: Pavel Roskin <[email protected]>
Acked-by: David Sterba <[email protected]>
Cc: Grant Edwards <[email protected]>
Cc: Stanislaw Gruszka <[email protected]>
Cc: Hal Murray <[email protected]>
Cc: <[email protected]> # 3.12.x+
Signed-off-by: Peter Hurley <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left o

tty: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will neede

TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: move low_latency to tty_port

One point is to have less places where we actually need tty pointer.
The other is that low_latency is bound to buffer processing and
buffers are now in tty_port. So

TTY: move low_latency to tty_port

One point is to have less places where we actually need tty pointer.
The other is that low_latency is bound to buffer processing and
buffers are now in tty_port. So it makes sense to move low_latency to
tty_port too.

Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: switch tty_insert_flip_string

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will nee

TTY: switch tty_insert_flip_string

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_string this time.

Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: call tty_port_destroy in the rest of drivers

After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called w

TTY: call tty_port_destroy in the rest of drivers

After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.

To be sure, the TTY buffers (and later some stuff) are gone along with
the tty_port, we have to call tty_port_destroy at tear-down places.
This is mostly where the structure containing a tty_port is freed.
This patch does exactly that -- put tty_port_destroy at those places.

Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: use tty_port_register_device

Currently we have no way to assign tty->port while performing tty
installation. There are two ways to provide the link tty_struct =>
tty_port. Either by calling tty

TTY: use tty_port_register_device

Currently we have no way to assign tty->port while performing tty
installation. There are two ways to provide the link tty_struct =>
tty_port. Either by calling tty_port_install from tty->ops->install or
tty_port_register_device called instead of tty_register_device when
the device is being set up after connected.

In this patch we modify most of the drivers to do the latter. When the
drivers use tty_register_device and we have tty_port already, we
switch to tty_port_register_device. So we have the tty_struct =>
tty_port link for free for those.

Signed-off-by: Jiri Slaby <[email protected]>
Acked-by: Alan Cox <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: ipwireless, use tty from tty_port

It does not make the driver less racy though. Close and hangup should
be rewritten and tty refcounting used properly.

Signed-off-by: Jiri Slaby <[email protected]

TTY: ipwireless, use tty from tty_port

It does not make the driver less racy though. Close and hangup should
be rewritten and tty refcounting used properly.

Signed-off-by: Jiri Slaby <[email protected]>
Cc: Jiri Kosina <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: ipwireless, add tty_port

And use count from that.

Signed-off-by: Jiri Slaby <[email protected]>
Cc: Jiri Kosina <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroa

TTY: ipwireless, add tty_port

And use count from that.

Signed-off-by: Jiri Slaby <[email protected]>
Cc: Jiri Kosina <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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TTY: ipwireless, move prints to appropriate places

There are two functions which only print a status. Let us do that
directly at places where they are called.

Signed-off-by: Jiri Slaby <jslaby@suse

TTY: ipwireless, move prints to appropriate places

There are two functions which only print a status. Let us do that
directly at places where they are called.

Signed-off-by: Jiri Slaby <[email protected]>
Cc: Jiri Kosina <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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