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Commit 87515772 authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
Browse files

earlycon: 8250: Fix command line regression 



Restore undocumented behavior of kernel command line parameters of
the forms:
    console=uart[8250],io|mmio|mmio32,<addr>[,options]
    console=uart[8250],<addr>[,options]
where 'options' have not been specified; in this case, the hardware
is assumed to be initialized.

Fixes: c7cef0a8 ("console: Add extensible console matching")
Reported-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 99492c39

drivers/tty/serial/8250/8250_core.c

+24 −7
Original line number Diff line number Diff line
@@ -3412,9 +3412,23 @@ static void univ8250_console_write(struct console *co, const char *s, 
	serial8250_console_write(up, s, count);

}



static int serial8250_console_setup(struct uart_8250_port *up, char *options)

static unsigned int probe_baud(struct uart_port *port)

{

	unsigned char lcr, dll, dlm;

	unsigned int quot;



	lcr = serial_port_in(port, UART_LCR);

	serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);

	dll = serial_port_in(port, UART_DLL);

	dlm = serial_port_in(port, UART_DLM);

	serial_port_out(port, UART_LCR, lcr);



	quot = (dlm << 8) | dll;

	return (port->uartclk / 16) / quot;

}



static int serial8250_console_setup(struct uart_port *port, char *options, bool probe)

{

	struct uart_port *port = &up->port;

	int baud = 9600;

	int bits = 8;

	int parity = 'n';
@@ -3425,13 +3439,15 @@ static int serial8250_console_setup(struct uart_8250_port *up, char *options) 


	if (options)

		uart_parse_options(options, &baud, &parity, &bits, &flow);

	else if (probe)

		baud = probe_baud(port);



	return uart_set_options(port, port->cons, baud, parity, bits, flow);

}



static int univ8250_console_setup(struct console *co, char *options)

{

	struct uart_8250_port *up;

	struct uart_port *port;



	/*

	 * Check whether an invalid uart number has been specified, and
@@ -3440,11 +3456,11 @@ static int univ8250_console_setup(struct console *co, char *options) 
	 */

	if (co->index >= nr_uarts)

		co->index = 0;

	up = &serial8250_ports[co->index];

	port = &serial8250_ports[co->index].port;

	/* link port to console */

	up->port.cons = co;

	port->cons = co;



	return serial8250_console_setup(up, options);

	return serial8250_console_setup(port, options, false);

}



/**
@@ -3491,7 +3507,8 @@ static int univ8250_console_match(struct console *co, char *name, int idx, 
			continue;



		co->index = i;

		return univ8250_console_setup(co, options);

		port->cons = co;

		return serial8250_console_setup(port, options, true);

	}



	return -ENODEV;

drivers/tty/serial/8250/8250_early.c

+0 −19
Original line number Diff line number Diff line
@@ -105,21 +105,6 @@ static void __init early_serial8250_write(struct console *console, 
		serial8250_early_out(port, UART_IER, ier);

}



static unsigned int __init probe_baud(struct uart_port *port)

{

	unsigned char lcr, dll, dlm;

	unsigned int quot;



	lcr = serial8250_early_in(port, UART_LCR);

	serial8250_early_out(port, UART_LCR, lcr | UART_LCR_DLAB);

	dll = serial8250_early_in(port, UART_DLL);

	dlm = serial8250_early_in(port, UART_DLM);

	serial8250_early_out(port, UART_LCR, lcr);



	quot = (dlm << 8) | dll;

	return (port->uartclk / 16) / quot;

}



static void __init init_port(struct earlycon_device *device)

{

	struct uart_port *port = &device->port;
@@ -151,10 +136,6 @@ static int __init early_serial8250_setup(struct earlycon_device *device, 
		struct uart_port *port = &device->port;

		unsigned int ier;



		device->baud = probe_baud(&device->port);

		snprintf(device->options, sizeof(device->options), "%u",

			 device->baud);



		/* assume the device was initialized, only mask interrupts */

		ier = serial8250_early_in(port, UART_IER);

		serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);