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

serial: introduce uart_port_lock() guard()s

2025-08-17T10:46:25+00:00

Having this, guards like these work: guard(uart_port_lock_irq)(&up->port); or scoped_guard(uart_port_lock_irqsave, port) { ... } See e.g. "serial: 8250: use guard()s" later in this series. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20250814072456.182853-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: Remove unused uart_get_console

2025-06-19T11:24:16+00:00

uart_get_console() has been unused since 2019's commit bd0d9d159988 ("serial: remove ks8695 driver") Remove it, and it's associated docs. Signed-off-by: "Dr. David Alan Gilbert" Acked-by: Randy Dunlap Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20250608154654.73994-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman

serial: 8250: sanitize uart_port::serial_{in,out}() types

2025-06-17T11:42:34+00:00

uart_port::{serial_in,serial_out} (and plat_serial8250_port::* likewise) historically use: * 'unsigned int' for 32-bit register values in reads and writes, and * 'int' for offsets. Make them sane such that: * 'u32' is used for register values, and * 'unsigned int' is used for offsets. While at it, name hooks' parameters, so it is clear what is what. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Ilpo Järvinen Cc: Andy Shevchenko Cc: Paul Cercueil Cc: Vladimir Zapolskiy Cc: Kunihiko Hayashi Cc: Masami Hiramatsu Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250611100319.186924-9-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: switch uart_port::iotype to enum uart_iotype

2025-04-25T11:46:31+00:00

The inline-defined constants look weird. Instead, define a proper enum for them and type uart_port::iotype as that enum. This allows for proper checking in switch-case labels (somewhere, a default or UPIO_UNKNOWN label needs to be added/handled). Signed-off-by: Jiri Slaby (SUSE) Link: https://lore.kernel.org/r/20250425111315.1036184-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: serial: handle HAS_IOPORT dependencies

2024-10-28T21:44:28+00:00

In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at compile time. We thus need to add HAS_IOPORT as dependency for those drivers using them unconditionally. Some 8250 serial drivers support MMIO only use, so fence only the parts requiring I/O ports and print an error message if a device can't be supported with the current configuration. Co-developed-by: Arnd Bergmann Signed-off-by: Arnd Bergmann Acked-by: Greg Kroah-Hartman Reviewed-by: Maciej W. Rozycki Signed-off-by: Niklas Schnelle Signed-off-by: Arnd Bergmann

serial: core: Acquire nbcon context in port->lock wrapper

2024-08-21T12:56:23+00:00

Currently the port->lock wrappers uart_port_lock(), uart_port_unlock() (and their variants) only lock/unlock the spin_lock. If the port is an nbcon console that has implemented the write_atomic() callback, the wrappers must also acquire/release the console context and mark the region as unsafe. This allows general port->lock synchronization to be synchronized against the nbcon write_atomic() callback. Note that __uart_port_using_nbcon() relies on the port->lock being held while a console is added and removed from the console list (i.e. all uart nbcon drivers *must* take the port->lock in their device_lock() callbacks). Signed-off-by: John Ogness Acked-by: Greg Kroah-Hartman Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20240820063001.36405-15-john.ogness@linutronix.de Signed-off-by: Petr Mladek

serial: core: Introduce wrapper to set @uart_port->cons

2024-08-21T12:56:23+00:00

Introduce uart_port_set_cons() as a wrapper to set @cons of a uart_port. The wrapper sets @cons under the port lock in order to prevent @cons from disappearing while another context is holding the port lock. This is necessary for a follow-up commit relating to the port lock wrappers, which rely on @cons not changing between lock and unlock. Signed-off-by: John Ogness Tested-by: Théo Lebrun # EyeQ5, AMBA-PL011 Acked-by: Greg Kroah-Hartman Reviewed-by: Petr Mladek Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20240820063001.36405-12-john.ogness@linutronix.de Signed-off-by: Petr Mladek

serial: core: Provide low-level functions to lock port

2024-08-21T12:56:23+00:00

It will be necessary at times for the uart nbcon console drivers to acquire the port lock directly (without the additional nbcon functionality of the port lock wrappers). These are special cases such as the implementation of the device_lock()/device_unlock() callbacks or for internal port lock wrapper synchronization. Provide low-level variants __uart_port_lock_irqsave() and __uart_port_unlock_irqrestore() for this purpose. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20240820063001.36405-11-john.ogness@linutronix.de Signed-off-by: Petr Mladek

serial: core: introduce uart_port_tx_limited_flags()

2024-06-24T14:14:48+00:00

Analogue to uart_port_tx_flags() introduced in commit 3ee07964d407 ("serial: core: introduce uart_port_tx_flags()"), add a _flags variant for uart_port_tx_limited(). Fixes: d11cc8c3c4b6 ("tty: serial: use uart_port_tx_limited()") Cc: stable@vger.kernel.org Signed-off-by: Jonas Gorski Signed-off-by: Doug Brown Link: https://lore.kernel.org/r/20240606195632.173255-3-doug@schmorgal.com Signed-off-by: Greg Kroah-Hartman

Revert "serial: core: only stop transmit when HW fifo is empty"

2024-06-24T14:14:33+00:00

This reverts commit 7bfb915a597a301abb892f620fe5c283a9fdbd77. This commit broke pxa and omap-serial, because it inhibited them from calling stop_tx() if their TX FIFOs weren't completely empty. This resulted in these two drivers hanging during transmits because the TX interrupt would stay enabled, and a new TX interrupt would never fire. Cc: stable@vger.kernel.org Fixes: 7bfb915a597a ("serial: core: only stop transmit when HW fifo is empty") Signed-off-by: Doug Brown Link: https://lore.kernel.org/r/20240606195632.173255-2-doug@schmorgal.com Signed-off-by: Greg Kroah-Hartman