kernel/linux.git/drivers/tty/serial/arc_uart.c, branch v6.6.131

serial: drivers: switch ch and flag to u8

2023-07-25T17:21:04+00:00

Now that the serial layer explicitly expects 'u8' for flags and characters, propagate this type to drivers' (RX) routines. Note that amba-pl011's, clps711x's and st-asc's 'ch' are left unchanged because 'ch' contains not only a character, but whole status. Signed-off-by: Jiri Slaby (SUSE) Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Richard Genoud Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Claudiu Beznea Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: Taichi Sugaya Cc: Takao Orito Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Kevin Cernekee Cc: Krzysztof Kozlowski Cc: Alim Akhtar Cc: Laxman Dewangan Cc: Thierry Reding Cc: Jonathan Hunter Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Orson Zhai Cc: Baolin Wang Cc: Chunyan Zhang Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: Hammer Hsieh Acked-by: Richard GENOUD Acked-by: Tobias Klauser Acked-by: Thierry Reding Acked-by: Maciej W. Rozycki Link: https://lore.kernel.org/r/20230712081811.29004-11-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: arc_uart: simplify flags handling in arc_serial_rx_chars()

2023-07-25T17:21:03+00:00

* move the declaration of flg (with the initializer) to the loop, so there is no need to reset it to TTY_NORMAL by an 'else' branch. * use TTY_NORMAL as initializer above, not a magic zero constant * remove the outer 'if' from this construct: if (S & (A | B)) { if (S & A) X; if (S & B) Y; } * drop unlikely() as I doubt it has any benefits here. If it does, provide numbers. All four make the code easier to read. Signed-off-by: Jiri Slaby (SUSE) Cc: Vineet Gupta Acked-by: Vineet Gupta Link: https://lore.kernel.org/r/20230712081811.29004-9-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: arc_uart: fix of_iomap leak in `arc_serial_probe`

2023-05-13T10:55:46+00:00

Smatch reports: drivers/tty/serial/arc_uart.c:631 arc_serial_probe() warn: 'port->membase' from of_iomap() not released on lines: 631. In arc_serial_probe(), if uart_add_one_port() fails, port->membase is not released, which would cause a resource leak. To fix this, I replace of_iomap with devm_platform_ioremap_resource. Fixes: 8dbe1d5e09a7 ("serial/arc: inline the probe helper") Signed-off-by: Ke Zhang Reviewed-by: Dongliang Mu Link: https://lore.kernel.org/r/20230428031636.44642-1-m202171830@hust.edu.cn Signed-off-by: Greg Kroah-Hartman

serial: arc_uart: Drop empty platform remove function

2023-01-17T18:12:38+00:00

A remove callback just returning 0 is equivalent to no remove callback at all. So drop the useless function. Signed-off-by: Uwe Kleine-König Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20221212212037.3773636-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

serial: arc: Use uart_xmit_advance()

2022-11-03T02:35:41+00:00

Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20221019091151.6692-11-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: make uart_console_write->putchar()'s character an unsigned char

2022-03-03T14:06:31+00:00

Currently, uart_console_write->putchar's second parameter (the character) is of type int. It makes little sense, provided uart_console_write() accepts the input string as "const char *s" and passes its content -- the characters -- to putchar(). So switch the character's type to unsigned char. We don't use char as that is signed on some platforms. That would cause troubles for drivers which (implicitly) cast the char to u16 when writing to the device. Sign extension would happen in that case and the value written would be completely different to the provided char. DZ is an example of such a driver -- on MIPS, it uses u16 for dz_out in dz_console_putchar(). Note we do the char -> uchar conversion implicitly in uart_console_write(). Provided we do not change size of the data type, sign extension does not happen there, so the problem is void. This makes the types consistent and unified with the rest of the uart layer, which uses unsigned char in most places already. One exception is xmit_buf, but that is going to be converted later. Cc: Paul Cercueil Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Ludovic Desroches Cc: Florian Fainelli Cc: bcm-kernel-feedback-list@broadcom.com Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Karol Gugala Cc: Mateusz Holenko Cc: Vladimir Zapolskiy Cc: Neil Armstrong Cc: Kevin Hilman Cc: Jerome Brunet Cc: Martin Blumenstingl Cc: Taichi Sugaya Cc: Takao Orito Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: "Andreas Färber" Cc: Manivannan Sadhasivam Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Andy Gross Cc: Bjorn Andersson Cc: Krzysztof Kozlowski Cc: Orson Zhai Cc: Baolin Wang Cc: Chunyan Zhang Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Michal Simek Acked-by: Richard Genoud [atmel_serial] Acked-by: Uwe Kleine-König Acked-by: Paul Cercueil Acked-by: Neil Armstrong # meson_serial Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220303080831.21783-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: cumulate and document tty_struct::flow* members

2021-05-13T14:57:16+00:00

Group the flow flags under a single struct called flow. The new struct contains 'stopped' and 'tco_stopped' bools which used to be bits in a bitfield. The struct also contains the lock protecting them to potentially share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. This is also the perfect time to start the documentation of tty_struct where all this lives. So we start by documenting what these bools actually serve for. And why we do all the alignment dances. Only the few up-to-date information from the Theodore's comment made it into this new Kerneldoc comment. Signed-off-by: Jiri Slaby Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Jonathan Corbet Cc: Arnd Bergmann Cc: Ulf Hansson Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Shawn Guo Cc: Sascha Hauer Cc: Vineet Gupta Cc: "Maciej W. Rozycki" Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

serial: arc_uart: drop low-latency workaround

2021-04-22T10:09:25+00:00

Commit 3fa1200851c7 ("tty: serial: arc: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Cc: Vineet Gupta Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20210421095509.3024-9-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

tty/serial: Migrate arc_uart to use has_sysrq

2019-12-18T14:04:45+00:00

The SUPPORT_SYSRQ ifdeffery is not nice as: - May create misunderstanding about sizeof(struct uart_port) between different objects - Prevents moving functions from serial_core.h - Reduces readability (well, it's ifdeffery - it's hard to follow) In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added. Initialise it in driver's probe and remove ifdeffery. Cc: Vineet Gupta Signed-off-by: Dmitry Safonov Link: https://lore.kernel.org/r/20191213000657.931618-12-dima@arista.com Signed-off-by: Greg Kroah-Hartman