diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2015-04-06 10:48:49 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-04-10 14:39:54 +0200 |
| commit | 87515772c33ee8a0cc08d984a7d2401eeff074cd (patch) | |
| tree | bde94a76edccf59cfe72e3858337a211ec098257 /drivers/tty/serial/8250/8250_core.c | |
| parent | 99492c39f39fc2d8c4ae36ecfb88d7de5d8106b5 (diff) | |
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: c7cef0a84912cab3c9df8 ("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>
Diffstat (limited to 'drivers/tty/serial/8250/8250_core.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index e0fb5f053d09..18142ee3c013 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -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; |