Re: [PATCH RESEND RESEND] thermal/of: support thermal zones w/o trips subnode

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 22/07/2023 14:25, Icenowy Zheng wrote:
> From: Icenowy Zheng <uwu@icenowy.me>
> 
> Although the current device tree binding of thermal zones require the
> trips subnode, the binding in kernel v5.15 does not require it, and many
> device trees shipped with the kernel, for example,
> allwinner/sun50i-a64.dtsi and mediatek/mt8183-kukui.dtsi in ARM64, still
> comply to the old binding and contain no trips subnode.
> 
> Allow the code to successfully register thermal zones w/o trips subnode
> for DT binding compatibility now.
> 
> Furtherly, the inconsistency between DTs and bindings should be resolved
> by either adding empty trips subnode or dropping the trips subnode
> requirement.
> 
> Fixes: d0c75fa2c17f ("thermal/of: Initialize trip points separately")
> Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
> ---
> 
> Unfortunately the code gets dropped by mailing lists again and again...
> 
> Sorry for the disturbance.
> 
>   drivers/thermal/thermal_of.c | 17 +++++++++++------
>   1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
> index 6fb14e521197..2c76df847e84 100644
> --- a/drivers/thermal/thermal_of.c
> +++ b/drivers/thermal/thermal_of.c
> @@ -127,15 +127,17 @@ static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *n
>   
>   	trips = of_get_child_by_name(np, "trips");
>   	if (!trips) {
> -		pr_err("Failed to find 'trips' node\n");
> -		return ERR_PTR(-EINVAL);
> +		pr_debug("Failed to find 'trips' node\n");
> +		*ntrips = 0;

set ntrips at the beginning of the function.

> +		return NULL;

return ERR_PTR(-ENXIO);

>   	}
>   
>   	count = of_get_child_count(trips);
>   	if (!count) {
> -		pr_err("No trip point defined\n");
> -		ret = -EINVAL;
> -		goto out_of_node_put;
> +		pr_debug("No trip point defined\n");
> +		of_node_put(trips);
> +		*ntrips = 0;
> +		return NULL;

Why not keep goto out_of_node_put ?

>   	}
>   
>   	tt = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
> @@ -519,7 +521,10 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *


The function should check the return value of thermal_of_trips_init()

If this one returns -ENXIO, it should pr_warn().

>   	of_ops->bind = thermal_of_bind;
>   	of_ops->unbind = thermal_of_unbind;
>   
> -	mask = GENMASK_ULL((ntrips) - 1, 0);
> +	if (ntrips)
> +		mask = GENMASK_ULL((ntrips) - 1, 0);
> +	else
> +		mask = 0;

	mask = ntrips ? GENMASK_ULL((ntrips) - 1, 0) : 0;

>   	tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
>   						     mask, data, of_ops, tzp,

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