On Mon, Feb 29, 2016 at 2:02 PM, Aleksey Makarov
<aleksey.makarov@xxxxxxxxxx> wrote:
> 'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port
> Console Redirection Table) [2] as a mandatory ACPI table that
> specifies the configuration of serial console.
>
> Parse this table and check if any registered console match the
> description. If it does, enable that console.
>
> Introduce a new function acpi_console_check(). At the uart port
> registration, this function checks if the ACPI SPCR table specifies
> its argument of type struct uart_port to be a console
> and if so calls add_preferred_console().
> + if (ACPI_FAILURE(status)) {
> + pr_err("could not get the table\n");
Is it worse to have on error level? Is it possible to have firmware
without this table? I think it would be a normal case for non-arm
world.
I'm also not sure if this message useful even on warn level.
> + return -ENOENT;
> + }
> +
> + if (table->header.revision < 2) {
> + err = -EINVAL;
> + pr_err("wrong table version\n");
And this one quite good to have, indeed.
> + * acpi_console_check - Check if uart matches the console specified by SPCR.
> + *
> + * @uport: uart port to check
> + *
Since you use sections, you may add:
+ * Description:
> + * This function checks if the ACPI SPCR table specifies @uport to be a console
> + * and if so calls add_preferred_console()
> + *
> + * Return: a non-error value if the console matches.
> @@ -2654,8 +2655,17 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
> spin_lock_init(&uport->lock);
> lockdep_set_class(&uport->lock, &port_lock_key);
> }
> - if (uport->cons && uport->dev)
> - of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
> +
> + /*
> + * Support both open FW and ACPI access to console definitions.
> + * Both of_console_check() and acpi_console_check() will call
> + * add_preferred_console() if a console definition is found.
> + */
> + if (uport->cons && uport->dev) {
> + if (!acpi_console_check(uport))
if (cond1) {
if (cond2) {
...
}
}
is equivalent to
if (cond1 && cond2) {
...
}
> + of_console_check(uport->dev->of_node, uport->cons->name,
> + uport->line);
> + }
--
With Best Regards,
Andy Shevchenko
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