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tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused() 

Tony noticed that the old omap-serial driver picked the uart "number"
based on the hint given from device tree or platform device's id.
The 8250 based omap driver doesn't do this because the core code does
not honour the ->line argument which is passed by the driver.

This patch aims to keep the same behaviour as with omap-serial. The
function will first try to use the line suggested ->line argument and
then fallback to the old strategy in case the port is taken.

That means the the third uart will always be ttyS2 even if the previous
two have not been enabled in DT.

Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sebastian Andrzej Siewior 2014-09-10 21:29:59 +02:00 committed by Greg Kroah-Hartman
parent 0aa525d118
commit 59b3e898dd
1 changed files with 5 additions and 0 deletions
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5
drivers/tty/serial/8250/8250_core.c
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@ -3516,6 +3516,11 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
if (uart_match_port(&serial8250_ports[i].port, port)) if (uart_match_port(&serial8250_ports[i].port, port))
return &serial8250_ports[i]; return &serial8250_ports[i];
/* try line number first if still available */
i = port->line;
if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN &&
serial8250_ports[i].port.iobase == 0)
return &serial8250_ports[i];
/* /*
* We didn't find a matching entry, so look for the first * We didn't find a matching entry, so look for the first
* free entry. We look for one which hasn't been previously * free entry. We look for one which hasn't been previously