usb: dwc2: Always disable regulators on driver teardown
If the dwc2 driver fails to probe after having enabled the regulators,
it ends up being unregistered with regulators enabled, something the
core regulator code is legitimately upset about:
dwc2
ff400000.usb: supply vusb_d not found, using dummy regulator
dwc2
ff400000.usb: supply vusb_a not found, using dummy regulator
dwc2
ff400000.usb: dwc2_core_reset: HANG! AHB Idle timeout GRSTCTL GRSTCTL_AHBIDLE
WARNING: CPU: 2 PID: 112 at drivers/regulator/core.c:2074 _regulator_put.part.0+0x16c/0x174
Modules linked in: dwc2(E+) dwc3(E) udc_core(E) rtc_hym8563(E) dwmac_generic(E) ulpi(E) usbcore(E) dwc3_meson_g12a(E) roles(E) meson_gx_mmc(E+) i2c_meson(E) mdio_mux_meson_g12a(E) mdio_mux(E) dwmac_meson8b(E) stmmac_platform(E) stmmac(E) mdio_xpcs(E) phylink(E) of_mdio(E) fixed_phy(E) libphy(E) pwm_regulator(E) fixed(E)
CPU: 2 PID: 112 Comm: systemd-udevd Tainted: G E 5.9.0-rc4-00102-g423583bc8cf9 #1840
Hardware name: amlogic w400/w400, BIOS 2020.04 05/22/2020
pstate:
80400009 (Nzcv daif +PAN -UAO BTYPE=--)
pc : _regulator_put.part.0+0x16c/0x174
lr : regulator_bulk_free+0x6c/0x9c
sp :
ffffffc012353820
x29:
ffffffc012353820 x28:
ffffff805a4b7000
x27:
ffffff8059c2eac0 x26:
ffffff8059c2e810
x25:
ffffff805a4b7d00 x24:
ffffffc008cf3028
x23:
ffffffc011729ef8 x22:
ffffff807e2761d8
x21:
ffffffc01171df78 x20:
ffffff805a4b7700
x19:
ffffff805a4b7700 x18:
0000000000000030
x17:
0000000000000000 x16:
0000000000000000
x15:
ffffff807ea8d178 x14:
3935312820435455
x13:
2038323a36313a37 x12:
ffffffffffffffff
x11:
0000000000000040 x10:
0000000000000007
x9 :
ffffffc0106f77d0 x8 :
ffffffffffffffe0
x7 :
ffffffffffffffff x6 :
0000000000017702
x5 :
ffffff805a4b7400 x4 :
0000000000000000
x3 :
ffffffc01171df78 x2 :
ffffff807ea8cc40
x1 :
0000000000000000 x0 :
0000000000000001
Call trace:
_regulator_put.part.0+0x16c/0x174
regulator_bulk_free+0x6c/0x9c
devm_regulator_bulk_release+0x28/0x3c
release_nodes+0x1c8/0x2c0
devres_release_all+0x44/0x6c
really_probe+0x1ec/0x504
driver_probe_device+0x100/0x170
device_driver_attach+0xcc/0xd4
__driver_attach+0xb0/0x17c
bus_for_each_dev+0x7c/0xd4
driver_attach+0x30/0x3c
bus_add_driver+0x154/0x250
driver_register+0x84/0x140
__platform_driver_register+0x54/0x60
dwc2_platform_driver_init+0x2c/0x1000 [dwc2]
do_one_initcall+0x54/0x2d0
do_init_module+0x68/0x29c
In order to fix this, tie the regulator disabling to the teardown
process by registering a devm action callback. This makes sure that
the regulators are disabled at the right time (just before they are
released).
Cc: Minas Harutyunyan <hminas@synopsys.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200914130634.2424496-1-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>