mpc52xx/serial: fix error paths in probe function

- error cases for mapbase and irq were unbundled
- mapped irq now gets disposed on error
- errors return ENODEV instead of EINVAL as they are not dependant on
  arguments

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
---
 drivers/serial/mpc52xx_uart.c |   27 +++++++++++++++++----------
 1 files changed, 17 insertions(+), 10 deletions(-)

On Thu, Nov 27, 2008 at 10:33 AM, Wolfram Sang <w.sang@pengutronix.de> wrote:
> - error cases for mapbase and irq were unbundled
> - mapped irq now gets disposed on error
> - errors return ENODEV instead of EINVAL as they are not dependant on
>  arguments
>
> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
> ---
>  drivers/serial/mpc52xx_uart.c |   27 +++++++++++++++++----------
>  1 files changed, 17 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
> index 3234100..93e8893 100644
> --- a/drivers/serial/mpc52xx_uart.c
> +++ b/drivers/serial/mpc52xx_uart.c
> @@ -1113,14 +1113,14 @@ mpc52xx_uart_of_probe(struct of_device *op, const struct of_device_id *match)
>                if (mpc52xx_uart_nodes[idx] == op->node)
>                        break;
>        if (idx >= MPC52xx_PSC_MAXNUM)
> -               return -EINVAL;
> +               return -ENODEV;
>        pr_debug("Found %s assigned to ttyPSC%x\n",
>                 mpc52xx_uart_nodes[idx]->full_name, idx);
>
>        uartclk = psc_ops->getuartclk(op->node);
>        if (uartclk == 0) {
>                dev_dbg(&op->dev, "Could not find uart clock frequency!\n");
> -               return -EINVAL;
> +               return -ENODEV;
>        }
>
>        /* Init the port structure */
> @@ -1142,22 +1142,29 @@ mpc52xx_uart_of_probe(struct of_device *op, const struct of_device_id *match)
>                return ret;
>
>        port->mapbase = res.start;
> +       if (!port->mapbase) {
> +               dev_err(&op->dev, "Could not allocate resources for PSC\n");
> +               return -ENODEV;
> +       }
> +
>        port->irq = irq_of_parse_and_map(op->node, 0);
> +       if (port->irq == NO_IRQ) {
> +               dev_err(&op->dev, "Could not get irq\n");
> +               return -ENODEV;
> +       }

Doesn't NO_IRQ imply polling, not an error?

>
>        dev_dbg(&op->dev, "mpc52xx-psc uart at %p, irq=%x, freq=%i\n",
>                (void *)port->mapbase, port->irq, port->uartclk);
>
> -       if ((port->irq == NO_IRQ) || !port->mapbase) {
> -               printk(KERN_ERR "Could not allocate resources for PSC\n");
> -               return -EINVAL;
> -       }
> -
>        /* Add the port to the uart sub-system */
>        ret = uart_add_one_port(&mpc52xx_uart_driver, port);
> -       if (!ret)
> -               dev_set_drvdata(&op->dev, (void *)port);
> +       if (ret) {
> +               irq_dispose_mapping(port->irq);
> +               return -ENODEV;
> +       }
>
> -       return ret;
> +       dev_set_drvdata(&op->dev, (void *)port);
> +       return 0;
>  }
>
>  static int
> --
> 1.5.6.5
>
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> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>

On Thu, Nov 27, 2008 at 11:40:55AM -0500, Jon Smirl wrote:

> > +       if (port->irq == NO_IRQ) {
> > +               dev_err(&op->dev, "Could not get irq\n");
> > +               return -ENODEV;
> > +       }
> 
> Doesn't NO_IRQ imply polling, not an error?

See below, I just copied the original behaviour. Having another look at
mpc52xx_uart_setup, I don't see any polling option there, so I think it
is correct to do this.

> 
> >
> >        dev_dbg(&op->dev, "mpc52xx-psc uart at %p, irq=%x, freq=%i\n",
> >                (void *)port->mapbase, port->irq, port->uartclk);
> >
> > -       if ((port->irq == NO_IRQ) || !port->mapbase) {
> > -               printk(KERN_ERR "Could not allocate resources for PSC\n");
> > -               return -EINVAL;
> > -       }

(Originaly dropout for NO_IRQ)

Regards,

   Wolfram