Re: [PATCH v3 5/5] usb: typec: tcpm/tcpci_maxim: deprecate WAR for setting charger mode

On 1/12/26 5:20 AM, Heikki Krogerus wrote:

Fri, Jan 09, 2026 at 06:16:57PM -0800, Amit Sunil Dhamne kirjoitti:

quoted

Hi Heikki,

Thanks for the review!

On 1/9/26 5:14 AM, Heikki Krogerus wrote:

quoted

Hi,

quoted

+	if (source) {
+		if (!regulator_is_enabled(chip->vbus_reg))
+			ret = regulator_enable(chip->vbus_reg);
+	} else {
+		if (regulator_is_enabled(chip->vbus_reg))
+			ret = regulator_disable(chip->vbus_reg);
+	}

It looks like you have to do one more round, so can drop the
regulator_is_enabled() checks and just always enable/disable it
unconditionally.

         if (source)
		ret = regulator_enable(chip->vbus_reg);
	else
		ret = regulator_disable(chip->vbus_reg);

The regulator framework uses refcounting on the number of enables. If
the number of times regulator is disabled > enabled, a warning will be
thrown. Also, I don't want to call regulator_enable more than once for
the same refcounting reason (will have to call disable those many number
of times to actually disable).

quoted

I don't think you need the check in any case, but if I've understood
this correctly, you should not use that check when the regulator does
not support that check because then the API claims it's always
enabled. So I guess in that case "if (!regulator_is_enabled())" may
not work as expected, and you may actually be left with a disabled
regulator. This may not be a problem on current platforms, but who
knows what happens in the future.

I don't think this should be an issue in the future as this driver is
specifically meant for max77759_tcpci device and should only be used
with max77759 charger (they both exist only in the same package). And
that the max77759_charger driver does implement the callback. However,
if you think that regulator_is_enabled() is unreliable, I could track
the state within the tcpci driver instead of calling
regulator_is_enabled() and call enable/disable regulator accordingly.

Let me know wdyt and I'll update the next revision accordingly.

Let's go with this then as is.

Sounds good. Thanks!

thanks,