kernel/linux.git/include/linux/tty_port.h, branch v6.12.80

tty: fix tty_port_tty_*hangup() kernel-doc

2026-01-08T09:15:01+00:00

commit 6241b49540a65a6d5274fa938fd3eb4cbfe2e076 upstream. The commit below added a new helper, but omitted to move (and add) the corressponding kernel-doc. Do it now. Signed-off-by: "Jiri Slaby (SUSE)" Fixes: 2b5eac0f8c6e ("tty: introduce and use tty_port_tty_vhangup() helper") Link: https://lore.kernel.org/all/b23d566c-09dc-7374-cc87-0ad4660e8b2e@linux.intel.com/ Reported-by: Ilpo Järvinen Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20250624080641.509959-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: introduce and use tty_port_tty_vhangup() helper

2026-01-08T09:14:56+00:00

[ Upstream commit 2b5eac0f8c6e79bc152c8804f9f88d16717013ab ] This code (tty_get -> vhangup -> tty_put) is repeated on few places. Introduce a helper similar to tty_port_tty_hangup() (asynchronous) to handle even vhangup (synchronous). And use it on those places. In fact, reuse the tty_port_tty_hangup()'s code and call tty_vhangup() depending on a new bool parameter. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Karsten Keil Cc: David Lin Cc: Johan Hovold Cc: Alex Elder Cc: Oliver Neukum Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20250611100319.186924-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 74098cc06e75 ("xhci: dbgtty: fix device unregister: fixup") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tty: switch tty_port::xmit_* to u8

2023-12-08T11:02:37+00:00

Both xmit_buf and xmit_fifo of struct tty_port should be u8. To conform to characters in the rest of the tty layer. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20231206073712.17776-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: core: Move tty and serdev to be children of serial core port device

2023-11-25T07:23:16+00:00

Let's move tty and serdev controller to be children of the serial core port device. This way the runtime PM usage count of a child device propagates to the serial hardware device. The tty and serdev devices are associated with a specific serial port of a serial hardware controller device, and we now have serial core hierarchy of controllers and ports. The tty device moves happily with just a change of the parent device and update of device_find_child() handling. The serdev device init needs some changes to separate the serial hardware controller device from the parent device. With this change the tty devices move under sysfs similar to this x86_64 qemu example of a diff of "find /sys -name ttyS*": /sys/class/tty/ttyS0 /sys/class/tty/ttyS3 /sys/class/tty/ttyS1 -/sys/devices/pnp0/00:04/tty/ttyS0 -/sys/devices/platform/serial8250/tty/ttyS2 -/sys/devices/platform/serial8250/tty/ttyS3 -/sys/devices/platform/serial8250/tty/ttyS1 +/sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty/ttyS0 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty/ttyS3 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty/ttyS1 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty/ttyS2 If a serdev device is used instead of a tty, it moves in a similar way. Suggested-by: Johan Hovold Cc: Maximilian Luz Cc: Rob Herring Signed-off-by: Tony Lindgren Link: https://lore.kernel.org/r/20231113080758.30346-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman

tty: make counts in tty_port_client_operations hooks size_t

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

The counts in tty_port_client_operations hooks' are currently represented by all 'int', 'unsigned int', and 'size_t'. Unify them all to unsigned 'size_t' for clarity. Note that size_t is used already in tty_buffer.c. So, eventually, it is spread for counts everywhere and this is the beginning. So the two changes namely: * ::receive_buf() is called from tty_ldisc_receive_buf(). And that expects values ">= 0" from ::receive_buf(), so switch its rettype to size_t is fine. tty_ldisc_receive_buf() types will be changed separately. * ::lookahead_buf()'s count comes from lookahead_bufs() and is already 'unsigned int'. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Rob Herring Link: https://lore.kernel.org/r/20230810091510.13006-11-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: make tty_port_client_operations operate with u8

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

The parameters are already unsigned chars. So make them explicitly u8s, as the rest is going to be unified to u8 eventually too. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Rob Herring Link: https://lore.kernel.org/r/20230810091510.13006-10-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: Call ->dtr_rts() parameter active consistently

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

Convert various parameter names for ->dtr_rts() and related functions from onoff, on, and raise to active. Reviewed-by: Jiri Slaby Acked-by: Ulf Hansson # For MMC Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230117090358.4796-12-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: Convert ->dtr_rts() to take bool argument

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

Convert the raise/on parameter in ->dtr_rts() to bool through the callchain. The parameter is used like bool. In USB serial, there remains a few implicit bool -> larger type conversions because some devices use u8 in their control messages. In moxa_tiocmget(), dtr variable was reused for line status which requires int so use a separate variable for status. Reviewed-by: Jiri Slaby Acked-by: Ulf Hansson # For MMC Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230117090358.4796-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: Convert ->carrier_raised() and callchains to bool

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

Return boolean from ->carrier_raised() instead of 0 and 1. Make the return type change also to tty_port_carrier_raised() that makes the ->carrier_raised() call (+ cd variable in moxa into which its return value is stored). Also cleans up a few unnecessary constructs related to this change: return xx ? 1 : 0; -> return xx; if (xx) return 1; return 0; -> return xx; Reviewed-by: Jiri Slaby Acked-by: Ulf Hansson # For MMC Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230117090358.4796-7-ilpo.jarvinen@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