[PATCH 30/33] serial: 8250: invert serial8250_register_8250_port() CIR condition

Jiri Slaby (SUSE)
2025-06-11T10:04:16Z

There is no point in a long 'if' in serial8250_register_8250_port() to
just return ENOSPC for PORT_8250_CIR ports. Invert the condition and
return immediately.

'gpios' variable was moved to its set location.

And return ENODEV instead of ENOSPC. The latter is a leftover from the
previous find-uart 'if'. The former makes a lot more sense in this case.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
drivers/tty/serial/8250/8250_core.c | 253 ++++++++++++++--------------
1 file changed, 127 insertions(+), 126 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 2bac9c7827de..10f25bae9f46 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -725,139 +725,140 @@ int serial8250_register_8250_port(const struct uart_8250_port *up)
nr_uarts++;
}

- if (uart->port.type != PORT_8250_CIR) {
- struct mctrl_gpios *gpios;
-
- if (uart->port.dev)
- uart_remove_one_port(&serial8250_reg, &uart->port);
-
- uart->port.ctrl_id = up->port.ctrl_id;
- uart->port.port_id = up->port.port_id;
- uart->port.iobase = up->port.iobase;
- uart->port.membase = up->port.membase;
- uart->port.irq = up->port.irq;
- uart->port.irqflags = up->port.irqflags;
- uart->port.uartclk = up->port.uartclk;
- uart->port.fifosize = up->port.fifosize;
- uart->port.regshift = up->port.regshift;
- uart->port.iotype = up->port.iotype;
- uart->port.flags = up->port.flags | UPF_BOOT_AUTOCONF;
- uart->bugs = up->bugs;
- uart->port.mapbase = up->port.mapbase;
- uart->port.mapsize = up->port.mapsize;
- uart->port.private_data = up->port.private_data;
- uart->tx_loadsz = up->tx_loadsz;
- uart->capabilities = up->capabilities;
- uart->port.throttle = up->port.throttle;
- uart->port.unthrottle = up->port.unthrottle;
- uart->port.rs485_config = up->port.rs485_config;
- uart->port.rs485_supported = up->port.rs485_supported;
- uart->port.rs485 = up->port.rs485;
- uart->rs485_start_tx = up->rs485_start_tx;
- uart->rs485_stop_tx = up->rs485_stop_tx;
- uart->lsr_save_mask = up->lsr_save_mask;
- uart->dma = up->dma;
-
- /* Take tx_loadsz from fifosize if it wasn't set separately */
- if (uart->port.fifosize && !uart->tx_loadsz)
- uart->tx_loadsz = uart->port.fifosize;
-
- if (up->port.dev) {
- uart->port.dev = up->port.dev;
- ret = uart_get_rs485_mode(&uart->port);
- if (ret)
- goto err;
- }
+ if (uart->port.type == PORT_8250_CIR) {
+ ret = -ENODEV;
+ goto unlock;
+ }

- if (up->port.flags & UPF_FIXED_TYPE)
- uart->port.type = up->port.type;
+ if (uart->port.dev)
+ uart_remove_one_port(&serial8250_reg, &uart->port);
+
+ uart->port.ctrl_id = up->port.ctrl_id;
+ uart->port.port_id = up->port.port_id;
+ uart->port.iobase = up->port.iobase;
+ uart->port.membase = up->port.membase;
+ uart->port.irq = up->port.irq;
+ uart->port.irqflags = up->port.irqflags;
+ uart->port.uartclk = up->port.uartclk;
+ uart->port.fifosize = up->port.fifosize;
+ uart->port.regshift = up->port.regshift;
+ uart->port.iotype = up->port.iotype;
+ uart->port.flags = up->port.flags | UPF_BOOT_AUTOCONF;
+ uart->bugs = up->bugs;
+ uart->port.mapbase = up->port.mapbase;
+ uart->port.mapsize = up->port.mapsize;
+ uart->port.private_data = up->port.private_data;
+ uart->tx_loadsz = up->tx_loadsz;
+ uart->capabilities = up->capabilities;
+ uart->port.throttle = up->port.throttle;
+ uart->port.unthrottle = up->port.unthrottle;
+ uart->port.rs485_config = up->port.rs485_config;
+ uart->port.rs485_supported = up->port.rs485_supported;
+ uart->port.rs485 = up->port.rs485;
+ uart->rs485_start_tx = up->rs485_start_tx;
+ uart->rs485_stop_tx = up->rs485_stop_tx;
+ uart->lsr_save_mask = up->lsr_save_mask;
+ uart->dma = up->dma;
+
+ /* Take tx_loadsz from fifosize if it wasn't set separately */
+ if (uart->port.fifosize && !uart->tx_loadsz)
+ uart->tx_loadsz = uart->port.fifosize;
+
+ if (up->port.dev) {
+ uart->port.dev = up->port.dev;
+ ret = uart_get_rs485_mode(&uart->port);
+ if (ret)
+ goto err;
+ }

- /*
- * Only call mctrl_gpio_init(), if the device has no ACPI
- * companion device
- */
- if (!has_acpi_companion(uart->port.dev)) {
- gpios = mctrl_gpio_init(&uart->port, 0);
- if (IS_ERR(gpios)) {
- ret = PTR_ERR(gpios);
- goto err;
- } else {
- uart->gpios = gpios;
- }
- }
+ if (up->port.flags & UPF_FIXED_TYPE)
+ uart->port.type = up->port.type;

- serial8250_set_defaults(uart);
-
- /* Possibly override default I/O functions. */
- if (up->port.serial_in)
- uart->port.serial_in = up->port.serial_in;
- if (up->port.serial_out)
- uart->port.serial_out = up->port.serial_out;
- if (up->port.handle_irq)
- uart->port.handle_irq = up->port.handle_irq;
- /* Possibly override set_termios call */
- if (up->port.set_termios)
- uart->port.set_termios = up->port.set_termios;
- if (up->port.set_ldisc)
- uart->port.set_ldisc = up->port.set_ldisc;
- if (up->port.get_mctrl)
- uart->port.get_mctrl = up->port.get_mctrl;
- if (up->port.set_mctrl)
- uart->port.set_mctrl = up->port.set_mctrl;
- if (up->port.get_divisor)
- uart->port.get_divisor = up->port.get_divisor;
- if (up->port.set_divisor)
- uart->port.set_divisor = up->port.set_divisor;
- if (up->port.startup)
- uart->port.startup = up->port.startup;
- if (up->port.shutdown)
- uart->port.shutdown = up->port.shutdown;
- if (up->port.pm)
- uart->port.pm = up->port.pm;
- if (up->port.handle_break)
- uart->port.handle_break = up->port.handle_break;
- if (up->dl_read)
- uart->dl_read = up->dl_read;
- if (up->dl_write)
- uart->dl_write = up->dl_write;
-
- if (uart->port.type != PORT_8250_CIR) {
- if (uart_console_registered(&uart->port))
- pm_runtime_get_sync(uart->port.dev);
-
- if (serial8250_isa_config != NULL)
- serial8250_isa_config(0, &uart->port,
- &uart->capabilities);
-
- serial8250_apply_quirks(uart);
- ret = uart_add_one_port(&serial8250_reg,
- &uart->port);
- if (ret)
- goto err;
-
- ret = uart->port.line;
+ /*
+ * Only call mctrl_gpio_init(), if the device has no ACPI
+ * companion device
+ */
+ if (!has_acpi_companion(uart->port.dev)) {
+ struct mctrl_gpios *gpios = mctrl_gpio_init(&uart->port, 0);
+ if (IS_ERR(gpios)) {
+ ret = PTR_ERR(gpios);
+ goto err;
} else {
- dev_info(uart->port.dev,
- "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
- uart->port.iobase,
- (unsigned long long)uart->port.mapbase,
- uart->port.irq);
-
- ret = 0;
+ uart->gpios = gpios;
}
+ }

- if (!uart->lsr_save_mask)
- uart->lsr_save_mask = LSR_SAVE_FLAGS; /* Use default LSR mask */
+ serial8250_set_defaults(uart);
+
+ /* Possibly override default I/O functions. */
+ if (up->port.serial_in)
+ uart->port.serial_in = up->port.serial_in;
+ if (up->port.serial_out)
+ uart->port.serial_out = up->port.serial_out;
+ if (up->port.handle_irq)
+ uart->port.handle_irq = up->port.handle_irq;
+ /* Possibly override set_termios call */
+ if (up->port.set_termios)
+ uart->port.set_termios = up->port.set_termios;
+ if (up->port.set_ldisc)
+ uart->port.set_ldisc = up->port.set_ldisc;
+ if (up->port.get_mctrl)
+ uart->port.get_mctrl = up->port.get_mctrl;
+ if (up->port.set_mctrl)
+ uart->port.set_mctrl = up->port.set_mctrl;
+ if (up->port.get_divisor)
+ uart->port.get_divisor = up->port.get_divisor;
+ if (up->port.set_divisor)
+ uart->port.set_divisor = up->port.set_divisor;
+ if (up->port.startup)
+ uart->port.startup = up->port.startup;
+ if (up->port.shutdown)
+ uart->port.shutdown = up->port.shutdown;
+ if (up->port.pm)
+ uart->port.pm = up->port.pm;
+ if (up->port.handle_break)
+ uart->port.handle_break = up->port.handle_break;
+ if (up->dl_read)
+ uart->dl_read = up->dl_read;
+ if (up->dl_write)
+ uart->dl_write = up->dl_write;

- /* Initialise interrupt backoff work if required */
- if (up->overrun_backoff_time_ms > 0) {
- uart->overrun_backoff_time_ms =
- up->overrun_backoff_time_ms;
- INIT_DELAYED_WORK(&uart->overrun_backoff,
- serial_8250_overrun_backoff_work);
- } else {
- uart->overrun_backoff_time_ms = 0;
- }
+ if (uart->port.type != PORT_8250_CIR) {
+ if (uart_console_registered(&uart->port))
+ pm_runtime_get_sync(uart->port.dev);
+
+ if (serial8250_isa_config != NULL)
+ serial8250_isa_config(0, &uart->port,
+ &uart->capabilities);
+
+ serial8250_apply_quirks(uart);
+ ret = uart_add_one_port(&serial8250_reg,
+ &uart->port);
+ if (ret)
+ goto err;
+
+ ret = uart->port.line;
+ } else {
+ dev_info(uart->port.dev,
+ "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
+ uart->port.iobase,
+ (unsigned long long)uart->port.mapbase,
+ uart->port.irq);
+
+ ret = 0;
+ }
+
+ if (!uart->lsr_save_mask)
+ uart->lsr_save_mask = LSR_SAVE_FLAGS; /* Use default LSR mask */
+
+ /* Initialise interrupt backoff work if required */
+ if (up->overrun_backoff_time_ms > 0) {
+ uart->overrun_backoff_time_ms =
+ up->overrun_backoff_time_ms;
+ INIT_DELAYED_WORK(&uart->overrun_backoff,
+ serial_8250_overrun_backoff_work);
+ } else {
+ uart->overrun_backoff_time_ms = 0;
}

unlock:
--
2.49.0