From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Amit Sunil Dhamne <amitsd@google.com>
Cc: "André Draszik" <andre.draszik@linaro.org>,
"Lee Jones" <lee@kernel.org>, "Rob Herring" <robh@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Conor Dooley" <conor+dt@kernel.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Jagan Sridharan" <badhri@google.com>,
"Mark Brown" <broonie@kernel.org>,
"Matti Vaittinen" <mazziesaccount@gmail.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Sebastian Reichel" <sre@kernel.org>,
"Peter Griffin" <peter.griffin@linaro.org>,
"Tudor Ambarus" <tudor.ambarus@linaro.org>,
"Alim Akhtar" <alim.akhtar@samsung.com>,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
linux-usb@vger.kernel.org, linux-pm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org,
"RD Babiera" <rdbabiera@google.com>,
"Kyle Tso" <kyletso@google.com>
Subject: Re: [PATCH v10 6/6] usb: typec: tcpm/tcpci_maxim: deprecate WAR for setting charger mode
Date: Tue, 7 Apr 2026 15:24:39 +0300 [thread overview]
Message-ID: <adT3h8ZEQh_mFi5j@kuha> (raw)
In-Reply-To: <017b8552-87e2-4409-ae34-9a3ab7365a68@google.com>
Hi Amit,
On Thu, Apr 02, 2026 at 11:47:30AM -0700, Amit Sunil Dhamne wrote:
> Hi Heikki,
>
> On 4/2/26 7:33 AM, Heikki Krogerus wrote:
> > Hi Amit,
> >
> > > +static int get_vbus_regulator_handle(struct max_tcpci_chip *chip)
> > > +{
> > > + if (IS_ERR_OR_NULL(chip->vbus_reg)) {
> > > + chip->vbus_reg = devm_regulator_get_exclusive(chip->dev,
> > > + "vbus");
> > Sorry to go back to this, but why can't you just get the regulator in
> > max_tcpci_probe()?
>
> Thanks for calling this out. This was an intentional design decision to
> break a circular dependency.
>
> The charger driver is guaranteed to probe after the TCPC driver due to a
> power supply dependency (the TCPC is a supplier of power for the Battery
> Charger). However, the charger driver is also the regulator provider for
> VBUS out (when Type-C goes into source mode).
>
> Because of this, the regulator handle will not be available during the TCPC
> driver's probe. If we tried to fetch it in max_tcpci_probe() and returned
> -EPROBE_DEFER, it would create a probe deadlock, as the charger would then
> never probe. Therefore, I made the decision to get the regulator handle
> lazily and on-demand.
Got it. Thanks for the explanation!
--
heikki
prev parent reply other threads:[~2026-04-07 12:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-31 23:22 [PATCH v10 0/6] Introduce MAX77759 charger driver Amit Sunil Dhamne via B4 Relay
2026-03-31 23:22 ` [PATCH v10 1/6] dt-bindings: mfd: maxim,max77759: reference power-supply schema and add regulator property Amit Sunil Dhamne via B4 Relay
2026-03-31 23:22 ` [PATCH v10 2/6] dt-bindings: usb: maxim,max33359: Add supply property for vbus Amit Sunil Dhamne via B4 Relay
2026-03-31 23:22 ` [PATCH v10 3/6] mfd: max77759: add register bitmasks and modify irq configs for charger Amit Sunil Dhamne via B4 Relay
2026-03-31 23:22 ` [PATCH v10 4/6] lib/linear_ranges: Add linear_range_get_selector_high_array Amit Sunil Dhamne via B4 Relay
2026-03-31 23:22 ` [PATCH v10 5/6] power: supply: max77759: add charger driver Amit Sunil Dhamne via B4 Relay
2026-04-01 23:17 ` Sebastian Reichel
2026-04-02 1:25 ` Amit Sunil Dhamne
2026-03-31 23:22 ` [PATCH v10 6/6] usb: typec: tcpm/tcpci_maxim: deprecate WAR for setting charger mode Amit Sunil Dhamne via B4 Relay
2026-04-02 14:33 ` Heikki Krogerus
2026-04-02 18:47 ` Amit Sunil Dhamne
2026-04-07 12:24 ` Heikki Krogerus [this message]
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