mirror_ubuntu-kernels/Documentation
Jiri Slaby (SUSE) 8275b48b27 tty: serial: introduce transmit helpers
Many serial drivers do the same thing:
* send x_char if set
* keep sending from the xmit circular buffer until either
  - the loop reaches the end of the xmit buffer
  - TX is stopped
  - HW fifo is full
* check for pending characters and:
  - wake up tty writers to fill for more data into xmit buffer
  - stop TX if there is nothing in the xmit buffer

The only differences are:
* how to write the character to the HW fifo
* the check of the end condition:
  - is the HW fifo full?
  - is limit of the written characters reached?

So unify the above into two helpers:
* uart_port_tx_limited() -- it performs the above taking the written
  characters limit into account, and
* uart_port_tx() -- the same as above, except it only checks the HW
  readiness, not the characters limit.

The HW specific operations (as stated as "differences" above) are passed
as arguments to the macros. They are:
* tx_ready -- returns true if HW can accept more data.
* put_char -- write a character to the device.
* tx_done -- when the write loop is done, perform arbitrary action
  before potential invocation of ops->stop_tx() happens.

Note that the above are macros. This means the code is generated in
place and the above 3 arguments are "inlined". I.e. no added penalty by
generating call instructions for every single character. Nor any
indirect calls. (As in some previous versions of this patchset.)

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20221004104927.14361-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03 03:32:40 +01:00
..
ABI memory tier, sysfs: rename attribute "nodes" to "nodelist" 2022-10-28 13:37:22 -07:00
accounting filemap: make the accounting of thrashing more consistent 2022-09-26 19:46:06 -07:00
admin-guide media: vivid.rst: loop_video is set on the capture devnode 2022-10-25 16:43:54 +01:00
arc
arm EFI updates for v6.1 2022-10-09 08:56:54 -07:00
arm64 arm64: errata: Add Cortex-A55 to the repeat tlbi list 2022-10-07 14:42:20 +01:00
block Documentation: document ublk user recovery feature 2022-10-18 05:12:26 -07:00
bpf Networking changes for 6.1. 2022-10-04 13:38:03 -07:00
cdrom
core-api overflow: Fix kern-doc markup for functions 2022-10-25 14:57:42 -07:00
cpu-freq
crypto
dev-tools linux-kselftest-kunit-6.1-rc1-2 2022-10-12 15:01:58 -07:00
devicetree Some pin control fixes for v6.1: 2022-10-24 11:48:30 -07:00
doc-guide Rust introduction for v6.1-rc1 2022-10-03 16:39:37 -07:00
driver-api tty: serial: introduce transmit helpers 2022-11-03 03:32:40 +01:00
fault-injection docs: notifier-error-inject: Correct test's name 2022-10-07 10:32:16 -06:00
fb Documentation: fb: udlfb: clean up text and formatting 2022-09-27 13:21:44 -06:00
features
filesystems A handful of relatively simple documentation fixes, plus a set of patches 2022-10-13 10:58:32 -07:00
firmware_class
firmware-guide Merge branches 'acpi-misc', 'acpi-tools' and 'acpi-docs' 2022-10-03 20:03:49 +02:00
fpga
gpu Immutable backlight-detect-refactor branch between acpi, drm-* and pdx86 2022-09-14 12:27:10 +01:00
hid
hwmon hwmon: (corsair-psu) Add USB id of the new HX1500i psu 2022-10-22 06:59:12 -07:00
i2c docs: i2c: slave-interface: return errno when handle I2C_SLAVE_WRITE_REQUESTED 2022-09-28 21:41:59 +02:00
ia64
iio docs: iio: add documentation for BNO055 driver 2022-09-21 18:42:56 +01:00
images
infiniband
input Merge branch 'next' into for-linus 2022-10-09 22:30:23 -07:00
isdn
kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
kernel-hacking
leds
litmus-tests
livepatch
locking Remove duplicate words inside documentation 2022-09-27 13:21:43 -06:00
loongarch
m68k
maintainer
mhi
mips
misc-devices
mm A handful of relatively simple documentation fixes, plus a set of patches 2022-10-13 10:58:32 -07:00
netlabel
networking Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
nios2
nvdimm
openrisc
parisc
PCI
pcmcia
peci
power
powerpc powerpc/64s: update cpu selection options 2022-09-28 19:22:10 +10:00
process docs: netdev: offer performance feedback to contributors 2022-10-24 11:03:44 +01:00
RCU There's not a huge amount of activity in the docs tree this time around, 2022-10-03 10:23:32 -07:00
riscv doc: RISC-V: Document that misaligned accesses are supported 2022-10-12 08:58:10 -07:00
rust x86: enable initial Rust support 2022-09-28 09:02:45 +02:00
s390 vfio/mdev: embedd struct mdev_parent in the parent data structure 2022-10-04 12:06:58 -06:00
scheduler docs: scheduler: Update new path for the sysctl knobs 2022-09-27 13:21:42 -06:00
scsi
security landlock: Fix documentation style 2022-09-29 18:43:04 +02:00
sh
sound
sparc
sphinx
sphinx-static
spi
staging docs: put atomic*.txt and memory-barriers.txt into the core-api book 2022-09-29 12:55:06 -06:00
target
timers
tools A handful of relatively simple documentation fixes, plus a set of patches 2022-10-13 10:58:32 -07:00
trace A handful of relatively simple documentation fixes, plus a set of patches 2022-10-13 10:58:32 -07:00
translations A handful of relatively simple documentation fixes, plus a set of patches 2022-10-13 10:58:32 -07:00
usb
userspace-api media fixes for v6.1-rc2 2022-10-22 15:30:15 -07:00
virt ARM: 2022-10-11 20:07:44 -07:00
w1 Documentation: W1: minor typo corrections 2022-09-27 13:21:44 -06:00
watchdog
x86 - Get rid of a single ksize() usage 2022-10-04 10:12:08 -07:00
xtensa
.gitignore
arch.rst
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py There's not a huge amount of activity in the docs tree this time around, 2022-10-03 10:23:32 -07:00
docutils.conf
dontdiff
index.rst Rust introduction for v6.1-rc1 2022-10-03 16:39:37 -07:00
Kconfig
Makefile
memory-barriers.txt
SubmittingPatches
subsystem-apis.rst docs: Rewrite the front page 2022-09-29 12:55:06 -06:00