Commit 79515869 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

serial: 8250: extract serial8250_initialize() 



serial8250_do_startup() initializes the ports in the middle of the
function. This code can be separated to serial8250_initialize(), so that
serial8250_do_startup() can be readable again.

Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250611100319.186924-17-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a194597c

drivers/tty/serial/8250/8250_port.c

+50 −53
Original line number Diff line number Diff line
@@ -2247,13 +2247,59 @@ static void serial8250_THRE_test(struct uart_port *port) 
		up->bugs |= UART_BUG_THRE;

}



int serial8250_do_startup(struct uart_port *port)

static void serial8250_initialize(struct uart_port *port)

{

	struct uart_8250_port *up = up_to_u8250p(port);

	unsigned long flags;

	unsigned char iir;

	bool lsr_TEMT, iir_NOINT;



	serial_port_out(port, UART_LCR, UART_LCR_WLEN8);



	uart_port_lock_irqsave(port, &flags);

	if (port->flags & UPF_FOURPORT) {

		if (!port->irq)

			port->mctrl |= TIOCM_OUT1;

	} else {

		/* Most PC uarts need OUT2 raised to enable interrupts. */

		if (port->irq)

			port->mctrl |= TIOCM_OUT2;

	}



	serial8250_set_mctrl(port, port->mctrl);



	/*

	 * Serial over Lan (SoL) hack:

	 * Intel 8257x Gigabit ethernet chips have a 16550 emulation, to be used for Serial Over

	 * Lan.  Those chips take a longer time than a normal serial device to signalize that a

	 * transmission data was queued. Due to that, the above test generally fails. One solution

	 * would be to delay the reading of iir. However, this is not reliable, since the timeout is

	 * variable. So, let's just don't test if we receive TX irq.  This way, we'll never enable

	 * UART_BUG_TXEN.

	 */

	if (!(port->quirks & UPQ_NO_TXEN_TEST)) {

		/* Do a quick test to see if we receive an interrupt when we enable the TX irq. */

		serial_port_out(port, UART_IER, UART_IER_THRI);

		lsr_TEMT = serial_port_in(port, UART_LSR) & UART_LSR_TEMT;

		iir_NOINT = serial_port_in(port, UART_IIR) & UART_IIR_NO_INT;

		serial_port_out(port, UART_IER, 0);



		if (lsr_TEMT && iir_NOINT) {

			if (!(up->bugs & UART_BUG_TXEN)) {

				up->bugs |= UART_BUG_TXEN;

				dev_dbg(port->dev, "enabling bad tx status workarounds\n");

			}

		} else {

			up->bugs &= ~UART_BUG_TXEN;

		}

	}



	uart_port_unlock_irqrestore(port, flags);

}



int serial8250_do_startup(struct uart_port *port)

{

	struct uart_8250_port *up = up_to_u8250p(port);

	int retval;

	u16 lsr;



	if (!port->fifosize)

		port->fifosize = uart_config[port->type].fifo_size;
@@ -2310,56 +2356,7 @@ int serial8250_do_startup(struct uart_port *port) 


	up->ops->setup_timer(up);



	/*

	 * Now, initialize the UART

	 */

	serial_port_out(port, UART_LCR, UART_LCR_WLEN8);



	uart_port_lock_irqsave(port, &flags);

	if (up->port.flags & UPF_FOURPORT) {

		if (!up->port.irq)

			up->port.mctrl |= TIOCM_OUT1;

	} else

		/*

		 * Most PC uarts need OUT2 raised to enable interrupts.

		 */

		if (port->irq)

			up->port.mctrl |= TIOCM_OUT2;



	serial8250_set_mctrl(port, port->mctrl);



	/*

	 * Serial over Lan (SoL) hack:

	 * Intel 8257x Gigabit ethernet chips have a 16550 emulation, to be

	 * used for Serial Over Lan.  Those chips take a longer time than a

	 * normal serial device to signalize that a transmission data was

	 * queued. Due to that, the above test generally fails. One solution

	 * would be to delay the reading of iir. However, this is not

	 * reliable, since the timeout is variable. So, let's just don't

	 * test if we receive TX irq.  This way, we'll never enable

	 * UART_BUG_TXEN.

	 */

	if (!(up->port.quirks & UPQ_NO_TXEN_TEST)) {

		/*

		 * Do a quick test to see if we receive an interrupt when we

		 * enable the TX irq.

		 */

		serial_port_out(port, UART_IER, UART_IER_THRI);

		lsr = serial_port_in(port, UART_LSR);

		iir = serial_port_in(port, UART_IIR);

		serial_port_out(port, UART_IER, 0);



		if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {

			if (!(up->bugs & UART_BUG_TXEN)) {

				up->bugs |= UART_BUG_TXEN;

				dev_dbg(port->dev, "enabling bad tx status workarounds\n");

			}

		} else {

			up->bugs &= ~UART_BUG_TXEN;

		}

	}



	uart_port_unlock_irqrestore(port, flags);

	serial8250_initialize(port);



	/*

	 * Clear the interrupt registers again for luck, and clear the