Re: [PATCH 01/11] resolve PXA<->8250 serial device address conflict

From: Heikki Krogerus
Date: Mon Dec 02 2013 - 04:03:17 EST


Hi,

On Sun, Dec 01, 2013 at 10:26:14AM +0400, Sergei Ianovich wrote:
> PXA serial ports have "standard" UART names (ttyS[0-3]), major
> device number (4) and first minor device number (64) by default.
>
> If the system has extra 8250 serial port hardware in addition
> to onboard PXA serial ports, default settings produce a device
> allocation conflict.
>
> The patch provides a configuration option which can move onboard
> ports out of the way of 8250_core by assigning a different (204)
> major number and corresponding device names (ttySA[0-3]).
>
> Signed-off-by: Sergei Ianovich <ynvich@xxxxxxxxx>
> ---
> drivers/tty/serial/Kconfig | 19 +++++++++++++++++++
> drivers/tty/serial/pxa.c | 22 ++++++++++++++++++----
> 2 files changed, 37 insertions(+), 4 deletions(-)
> diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c

<snip>

> --- a/drivers/tty/serial/pxa.c
> +++ b/drivers/tty/serial/pxa.c
> @@ -593,6 +593,20 @@ serial_pxa_type(struct uart_port *port)
> static struct uart_pxa_port *serial_pxa_ports[4];
> static struct uart_driver serial_pxa_reg;
>
> +#ifndef CONFIG_SERIAL_PXA_AS_TTYSA
> +
> +#define PXA_TTY_NAME "ttyS"
> +#define PXA_TTY_MAJOR TTY_MAJOR
> +#define PXA_TTY_MINOR 64
> +
> +#else
> +
> +#define PXA_TTY_NAME "ttySA"
> +#define PXA_TTY_MAJOR 204
> +#define PXA_TTY_MINOR 5
> +
> +#endif
> +
> #ifdef CONFIG_SERIAL_PXA_CONSOLE
>
> #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
> @@ -751,7 +765,7 @@ serial_pxa_console_setup(struct console *co, char *options)
> }
>
> static struct console serial_pxa_console = {
> - .name = "ttyS",
> + .name = PXA_TTY_NAME,
> .write = serial_pxa_console_write,
> .device = uart_console_device,
> .setup = serial_pxa_console_setup,
> @@ -792,9 +806,9 @@ static struct uart_ops serial_pxa_pops = {
> static struct uart_driver serial_pxa_reg = {
> .owner = THIS_MODULE,
> .driver_name = "PXA serial",
> - .dev_name = "ttyS",
> - .major = TTY_MAJOR,
> - .minor = 64,
> + .dev_name = PXA_TTY_NAME,
> + .major = PXA_TTY_MAJOR,
> + .minor = PXA_TTY_MINOR,
> .nr = 4,
> .cons = PXA_CONSOLE,
> };

If drivers/tty/serial/pxa.c was converted to an other probe driver for
the 8250, this would not be an issue.

Br,

--
heikki
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