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earlycon: 8250: Fix command line regression

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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: c7cef0a849 ("console: Add extensible console matching")
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Hurley 2015-04-06 10:48:49 -04:00 committed by Greg Kroah-Hartman
parent 99492c39f3
commit 87515772c3
2 changed files with 24 additions and 26 deletions
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31
drivers/tty/serial/8250/8250_core.c
View file

@ -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;

19
drivers/tty/serial/8250/8250_early.c
View file

@ -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);