Hi Miquel,
On Mon, 20 Jan 2025 at 03:34, Miquel Raynal miquel.raynal@bootlin.com wrote:
Hello Simon,
int power_domain_on(struct power_domain *power_domain) {
...
if (priv->on_count++ > 0)return 0;-EALREADY
...
int power_domain_off(struct power_domain *power_domain) {
...
if (priv->on_count-- > 1)return 0;-EBUSY
See how the regulator uclass does it.
I really does not understand why we would like to do that.
It is perfectly normal operation to call power_domain_on/off() on the same power domain several times in a row and there is no reason to return an error code. It is quite the opposite, the main reason for power domains is to act like shared regulators. Se while a regulator has one user and doing the same action on it several times does not make much sense and can be reported, that is not how power domains have been thought about in the first place.
I am not aware of any difference between these two subsystems. If we want a power domain to actually turn off, how many times do we need to call power_domain_off()? The function silently does nothing in many cases, so it is not deterministic. In the case where we *actually* want to turn the power domain off, we are at a loss as to what code to write.
Hence, I do not agree with returning error codes in these situations, they are misleading and they would have to be ignored anyway.
How about creating a power_domain_off_if_allowed() or power_domain_soft_off/on() or power_domain_req_off (for request)?
Regards, SImon