[PATCH] clocksource/drivers/sp804: avoid error on multiple instances
Robin Murphy
robin.murphy at arm.com
Wed Apr 27 08:42:12 PDT 2022
On 2022-04-27 15:27, Andre Przywara wrote:
> When a machine sports more than one SP804 timer instance, we only bring
> up the first one, since multiple timers of the same kind are not useful
> to Linux. As this is intentional behaviour, we should not return an
> error message, as we do today:
> ===============
> [ 0.000800] Failed to initialize '/bus at 8000000/motherboard-bus at 8000000/iofpga-bus at 300000000/timer at 120000': -22
> ===============
>
> Replace the -EINVAL return with an informative message and return 0
> instead.
>
> Also we do not reach the init function anymore if the DT node is
> disabled (as this is now handled by OF_DECLARE), so remove the explicit
> check for that case.
>
> This fixes a long standing bogus error when booting ARM's fastmodels.
And on Juno too, hooray! :)
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
> drivers/clocksource/timer-sp804.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
> index 401d592e85f5a..30cbc580e0448 100644
> --- a/drivers/clocksource/timer-sp804.c
> +++ b/drivers/clocksource/timer-sp804.c
> @@ -259,6 +259,12 @@ static int __init sp804_of_init(struct device_node *np, struct sp804_timer *time
> struct clk *clk1, *clk2;
> const char *name = of_get_property(np, "compatible", NULL);
>
> + if (initialized) {
> + pr_info("%s: only instantiating one timer\n",
> + of_node_full_name(np));
Nit: %pOF? However, do we really need to print anything at all? As it
is, the message already looks ambiguously like it might be saying that
this node *is* the one timer that we're instantiating, however we'll
have already logged the registration of an SP804 clocksource, so further
messages about what we *aren't* doing seem little more useful than
pr_info("not waxing an owl") IMO.
Cheers,
Robin.
> + return 0;
> + }
> +
> base = of_iomap(np, 0);
> if (!base)
> return -ENXIO;
> @@ -270,11 +276,6 @@ static int __init sp804_of_init(struct device_node *np, struct sp804_timer *time
> writel(0, timer1_base + timer->ctrl);
> writel(0, timer2_base + timer->ctrl);
>
> - if (initialized || !of_device_is_available(np)) {
> - ret = -EINVAL;
> - goto err;
> - }
> -
> clk1 = of_clk_get(np, 0);
> if (IS_ERR(clk1))
> clk1 = NULL;
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