On Fri, Jul 26, 2024 at 02:26:22PM +0200, Ahmad Fatoum wrote:
> We already have three CONSOLE_ACTIVATE options and every one of them has
> drawbacks:
>
> - ACTIVATE_ALL: May write barebox log to external devices like MCUs
> that don't expect it
>
> - ACTIVATE_FIRST: Not applicable for most systems that probe from
> device tree, where the order of probe is not necessarily fixed,
> so what console is first may change over updates
>
> - ACTIVATE_NONE: has a misleading name and may leave the user without
> any consoles at all if nothing else activates a console
>
> Let's add a new option and make it the default, which avoids all these
> issues: Like ACTIVATE_NONE, it expects board code, DT or environment to
> enable a console and if none of them do it falls back to activating all
> consoles, so the user isn't kept in the dark with an error instructing
> the user to fix this.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> Sent out second patch only by mistake instead of both...
> ---
> common/Kconfig | 19 ++++++++++++++++++-
> common/console.c | 27 +++++++++++++++++++++++++++
> 2 files changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/common/Kconfig b/common/Kconfig
> index 31360892aeef..2dda5ce5743a 100644
> --- a/common/Kconfig
> +++ b/common/Kconfig
> @@ -812,7 +812,7 @@ endchoice
> choice
> prompt "Console activation strategy"
> depends on CONSOLE_FULL
> - default CONSOLE_ACTIVATE_FIRST
> + default CONSOLE_ACTIVATE_ALL_FALLBACK
>
> config CONSOLE_ACTIVATE_FIRST
> bool
> @@ -831,6 +831,23 @@ config CONSOLE_ACTIVATE_ALL
> Only the first registered console will have the full startup
> log though.
>
> +config CONSOLE_ACTIVATE_ALL_FALLBACK
> + bool
> + prompt "activate all consoles as fallback"
> + help
> + This option is similar to CONFIG_CONSOLE_ACTIVATE_NONE in that it
> + leaves consoles disabled on startup. If by the end of barebox
> + startup, no consoles have been activated via board code, device
> + tree or environment, barebox will enable all registered consoles
> + as fallback, so the user has a chance to see output.
> +
> + This will be indicated by a fat error, so the user knows that
> + the configuration needs to be fixed. If you don't see any
> + output at all, consider trying again after enabling
> + CONFIG_CONSOLE_ACTIVATE_ALL, so consoles are activated immediately
> + at registration time and/or with CONFIG_DEBUG_LL, so barebox output
> + is written even before console drivers were registered.
> +
> config CONSOLE_ACTIVATE_NONE
> prompt "leave all consoles disabled"
> bool
> diff --git a/common/console.c b/common/console.c
> index 73b4c4d4db01..e83a3e1e2d7f 100644
> --- a/common/console.c
> +++ b/common/console.c
> @@ -450,6 +450,33 @@ int console_unregister(struct console_device *cdev)
> }
> EXPORT_SYMBOL(console_unregister);
>
> +static int console_activate_all_fallback(void)
> +{
> + int activate = CONSOLE_STDIOE;
> + struct console_device *cdev;
> +
> + for_each_console(cdev) {
> + if (cdev->f_active & (CONSOLE_STDOUT | CONSOLE_STDERR))
> + return 0;
> + }
> +
> + if (IS_ENABLED(CONFIG_CONSOLE_DISABLE_INPUT))
> + activate &= ~CONSOLE_STDIN;
> +
> + for_each_console(cdev)
> + console_set_active(cdev, activate);
> +
> + /*
> + * This is last resort, so the user is not kept in the dark.
> + * Writing to all consoles is a bad idea as the devices at the
> + * other side might get confused by it, thus the error log level.
> + */
> + pr_err("No consoles were activated. Activating all consoles as fallback!\n");
> +
> + return 0;
> +}
> +postenvironment_initcall(console_activate_all_fallback);
Shouldn't this code only run when CONSOLE_ACTIVATE_ALL_FALLBACK is
enabled?
Sascha
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