kernel/linux.git/include/linux/tty_ldisc.h, branch v6.19.11

tty/ldsem: Remove unused ldsem_down_write_trylock

2025-02-04T13:38:42+00:00

ldsem_down_write_trylock() was added in 2013 by commit 4898e640caf0 ("tty: Add timed, writer-prioritized rw semaphore") but hasn't been used. Remove it. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20250122012559.441006-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman

tty: ldops: unify to u8

2023-08-11T19:12:47+00:00

Some hooks in struct tty_ldisc_ops still reference buffers by 'unsigned char'. Unify to 'u8' as the rest of the tty layer does. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20230810091510.13006-32-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: use u8 for flags

2023-08-11T19:12:45+00:00

This makes all those 'char's an explicit 'u8'. This is part of the continuing unification of chars and flags to be consistent u8. This approaches tty_port_default_receive_buf(). Note that we do not change signedness as we compile with -funsigned-char. Signed-off-by: "Jiri Slaby (SUSE)" Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Max Staudt Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Dario Binacchi Cc: Andreas Koensgen Cc: Jeremy Kerr Cc: Matt Johnston Cc: Krzysztof Kozlowski Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Acked-by: Mark Brown Link: https://lore.kernel.org/r/20230810091510.13006-18-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: use u8 for chars

2023-08-11T19:12:45+00:00

This makes all those 'unsigned char's an explicit 'u8'. This is part of the continuing unification of chars and flags to be consistent u8. This approaches tty_port_default_receive_buf(). Flags to be next. Signed-off-by: "Jiri Slaby (SUSE)" Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: Max Staudt Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Dario Binacchi Cc: Andreas Koensgen Cc: Jeremy Kerr Cc: Matt Johnston Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Peter Ujfalusi Acked-by: Mark Brown Link: https://lore.kernel.org/r/20230810091510.13006-17-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: make tty_ldisc_ops::buf() hooks operate on size_t

2023-08-11T19:12:45+00:00

Count passed to tty_ldisc_ops::receive_buf*(), ::lookahead_buf(), and returned from ::receive_buf2() is expected to be size_t. So set it to size_t to unify with the rest of the code. Signed-off-by: "Jiri Slaby (SUSE)" Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Max Staudt Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Dario Binacchi Cc: Andreas Koensgen Cc: Jeremy Kerr Cc: Matt Johnston Cc: Krzysztof Kozlowski Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Acked-by: Mark Brown Link: https://lore.kernel.org/r/20230810091510.13006-16-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: ldisc: document that ldops are optional

2023-08-11T19:12:44+00:00

There is no need to provide any hook in struct tty_ldisc_ops. Document that and write down that read/write return EIO in that case. The rest is simply ignored. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230810091510.13006-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty/serial: Make ->dcd_change()+uart_handle_dcd_change() status bool active

2023-01-19T15:04:35+00:00

Convert status parameter for ->dcd_change() and uart_handle_dcd_change() to bool which matches to how the parameter is used. Rename status to active to better describe what the parameter means. Acked-by: Rodolfo Giometti Reviewed-by: Jiri Slaby Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230117090358.4796-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: Make ldisc ->set_termios() old ktermios const

2022-08-30T12:22:34+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/20220816115739.10928-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: Add closing marker into comment in tty_ldisc.h

2022-06-27T12:34:09+00:00

The closing `` is missing. Add it. Fixes: 6bb6fa6908eb ("tty: Implement lookahead to process XON/XOFF timely") Reported-by: Stephen Rothwell Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/9bc6d45d-48c8-519-1646-78ba22505b1f@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: Implement lookahead to process XON/XOFF timely

2022-06-10T11:51:31+00:00

When tty is not read from, XON/XOFF may get stuck into an intermediate buffer. As those characters are there to do software flow-control, it is not very useful. In the case where neither end reads from ttys, the receiving ends might not be able receive the XOFF characters and just keep sending more data to the opposite direction. This problem is almost guaranteed to occur with DMA which sends data in large chunks. If TTY is slow to process characters, that is, eats less than given amount in receive_buf, invoke lookahead for the rest of the chars to process potential XON/XOFF characters. We need to keep track of how many characters have been processed by the lookahead to avoid processing the flow control char again on the normal path. Bookkeeping occurs parallel on two layers (tty_buffer and n_tty) to avoid passing the lookahead_count through the whole call chain. When a flow-control char is processed, two things must occur: a) it must not be treated as normal char b) if not yet processed, flow-control actions need to be taken The return value of n_tty_receive_char_flow_ctrl() tells caller a), and b) is kept internal to n_tty_receive_char_flow_ctrl(). If characters were previous looked ahead, __receive_buf() makes two calls to the appropriate n_tty_receive_buf_* function. First call is made with lookahead_done=true for the characters that were subject to lookahead earlier and then with lookahead=false for the new characters. Either of the calls might be skipped when it has no characters to handle. Reported-by: Gilles Buloz Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220606153652.63554-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

kernel/linux.git/include/linux/tty_ldisc.h, branch v6.19.11

tty/ldsem: Remove unused ldsem_down_write_trylock

tty: ldops: unify to u8

tty: use u8 for flags

tty: use u8 for chars

tty: make tty_ldisc_ops::*buf*() hooks operate on size_t

tty: ldisc: document that ldops are optional

tty/serial: Make ->dcd_change()+uart_handle_dcd_change() status bool active

tty: Make ldisc ->set_termios() old ktermios const

tty: Add closing marker into comment in tty_ldisc.h

tty: Implement lookahead to process XON/XOFF timely

tty: make tty_ldisc_ops::buf() hooks operate on size_t