[PATCH] timer: orion-timer: Fix problem with early static variable

[Tony Dinh]

Hi Stefan,

On Wed, Dec 21, 2022 at 1:18 AM Stefan Roese <sr at denx.de> wrote:
>
> We've noticed that at least one Kirkwood board (Pogo v4) has problems
> with the new orion DM timer implementation. Debugging revealed that this
> issue is related with the static variable "early_init_done" which does
> not work correctly before relocation in all cases.
>
> This patch removes this static variable and replaces it's functionality
> via a function that detects if the timer is already initialized.
>
> Signed-off-by: Stefan Roese <sr at denx.de>
> Cc: Pali Rohár <pali at kernel.org>
> Cc: Michael Walle <michael at walle.cc>
> Cc: Tony Dinh <mibodhi at gmail.com>
> ---
>  drivers/timer/orion-timer.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/timer/orion-timer.c b/drivers/timer/orion-timer.c
> index d0eab3ce781d..6804bf0fa2cb 100644
> --- a/drivers/timer/orion-timer.c
> +++ b/drivers/timer/orion-timer.c
> @@ -23,15 +23,19 @@ struct orion_timer_priv {
>
>  #define MVEBU_TIMER_FIXED_RATE_25MHZ   25000000
>
> -static bool early_init_done __section(".data") = false;
> +static bool early_init_done(void *base)
> +{
> +       if (readl(base + TIMER_CTRL) & TIMER0_EN)
> +               return true;
> +       return false;
> +}
>
>  /* Common functions for early (boot) and DM based timer */
>  static void orion_timer_init(void *base, enum input_clock_type type)
>  {
>         /* Only init the timer once */
> -       if (early_init_done)
> +       if (early_init_done(base))
>                 return;
> -       early_init_done = true;
>
>         writel(~0, base + TIMER0_VAL);
>         writel(~0, base + TIMER0_RELOAD);
> --
> 2.39.0
>

I've tested with a couple Kirkwood boards, and they are working fine:
Pogo V4 (Kirkwood 88F6192) and Goflex Home (Kirkwood 88F6281). Note
that the Goflex Home does not have CONFIG_BOOTSTAGE (i.e. a regression
test, with a few sleep commands at the u-boot prompt).

Tested-by: Tony Dinh <mibodhi at gmail.com>

Thanks,
Tony