RE: [PATCH 09/11] phy: renesas: phy-rcar-gen3-usb2: Fix devm action registration for disabled VBUS regulator

[Biju Das]

Hi Claudiu,

+ stable <stable@xxxxxxxxxx>

> -----Original Message-----
> From: Claudiu Beznea <claudiu.beznea@xxxxxxxxx>
> Sent: 15 June 2026 10:37
> Subject: Re: [PATCH 09/11] phy: renesas: phy-rcar-gen3-usb2: Fix devm action registration for disabled
> VBUS regulator
> 
> Hi, Biju,
> 
> On 6/12/26 17:30, Biju wrote:
> > From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> >
> > devm_regulator_get_exclusive() initialises the regulator with
> > enable_count = 1, requiring the consumer to disable it before release.
> >
> > Previously, the devm disable action was only registered when the
> > regulator was explicitly enabled, causing the cleanup path to skip
> > decrementing enable_count on device removal when the regulator was
> > left disabled.
> >
> > Fix this by always registering the devm disable action when the
> > regulator is enabled (checked via regulator_is_enabled()), covering
> > both the explicitly-enabled case and the initial state set by
> > devm_regulator_get_exclusive().
> >
> > This fixes WARN_ON enable count during regulator release.
> >
> > Fixes: 24843404efe4 ("phy: renesas: phy-rcar-gen3-usb2: Control VBUS
> > for RZ/G2L SoCs")
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> 
> The approach in this patch don't solve the problem, at least on RZ/G3S. See [1] for logs.
> 
> I applied this patch on next-20260610:
> 
> git log --oneline -2
> afe09f11d549 (HEAD) phy: renesas: phy-rcar-gen3-usb2: Fix devm action registration for disabled VBUS
> regulator
> abe651837cb3 (tag: next-20260610, linux-next/master) Add linux-next specific files for 20260610
> 
> [1]
> https://github.com/claudiubeznea/logs/blob/2f1bab20407dfe6031385819ffeabfc4eac772bd/logs

This issue is introduced by the commit

eb9ac779830b223584 ("usb: renesas_usbhs: Fix synchronous external abort on unbind")

WARN_ON(enable_count) is related to regulator imbalance during unbind/bind cycle.

The above commit changed the code flow from

usbhsc_power_ctrl(priv, 0);
usbhs_platform_call(priv, hardware_exit, pdev);

to

usbhs_platform_call(priv, hardware_exit, pdev);
usbhsc_power_ctrl(priv, 0);


The function usbhs_*_hardware_exit(struct platform_device *pdev) sets
priv->phy to  NULL

and

usbhs_*_power_ctrl() has the below code and [1] is a dead code now after this commit.

if (!priv->phy)
		return -ENODEV;

	if (enable) {
		retval = phy_init(priv->phy);
		usbhs_bset(priv, SUSPMODE, SUSPM, SUSPM);
		udelay(100);	/* Wait for PLL to become stable */
		if (!retval)
			retval = phy_power_on(priv->phy);
	} else {
[1]
		usbhs_bset(priv, SUSPMODE, SUSPM, 0);
		phy_power_off(priv->phy);
		phy_exit(priv->phy);
	}

Cheers,
Biju