Hi Shimoda-san, Using a tree based on renesas-drivers-2019-06-04-v5.2-rc3, I started seeing the following warning during a second system suspend (s2idle): unbalanced disables for USB20_VBUS0 WARNING: CPU: 2 PID: 1162 at drivers/regulator/core.c:2593 _regulator_disable+0x58/0x174 Modules linked in: CPU: 2 PID: 1162 Comm: kworker/u16:22 Not tainted 5.2.0-rc3-salvator-x-02580-g25f69f634d1c7e7d #407 Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT) Workqueue: events_unbound async_run_entry_fn pstate: 40400005 (nZcv daif +PAN -UAO) pc : _regulator_disable+0x58/0x174 lr : _regulator_disable+0x58/0x174 sp : ffffff8012abb9d0 x29: ffffff8012abb9d0 x28: ffffff80110fa0c0 x27: 0000000000000000 x26: ffffff8010cecf66 x25: 0000000000000001 x24: 0000000000000002 x23: 0000000000000001 x22: ffffff801100e000 x21: ffffffc6f80ca700 x20: ffffffc6f80ae800 x19: ffffffc6f80ae800 x18: 000000000000000a x17: 0000000000000000 x16: 0000000000000000 x15: 000000000002da16 x14: 0720072007200720 x13: 0720072007200720 x12: ffffff8011038000 x11: ffffff8011b412e1 x10: 0000000000000044 x9 : 0000000000000028 x8 : ffffff801112187c x7 : 0000000000000001 x6 : 0000000000000000 x5 : ffffffc6ff70d240 x4 : 0000000000000001 x3 : 0000000000000007 x2 : 0000000000000007 x1 : 7a369ee2b9d96e00 x0 : 0000000000000000 Call trace: _regulator_disable+0x58/0x174 regulator_disable+0x40/0x78 rcar_gen3_phy_usb2_power_off+0x40/0x50 phy_power_off+0x50/0xb4 usb_phy_roothub_power_off+0x38/0x44 usb_phy_roothub_suspend+0x1c/0x48 hcd_bus_suspend+0xc8/0x15c generic_suspend+0x14/0x54 usb_suspend_both+0xec/0x208 usb_suspend+0xe0/0x118 usb_dev_suspend+0x10/0x18 dpm_run_callback+0x170/0x2e8 __device_suspend+0x18c/0x594 async_suspend+0x28/0xa0 async_run_entry_fn+0x4c/0x120 process_one_work+0x354/0x5b4 worker_thread+0x21c/0x324 kthread+0x120/0x130 ret_from_fork+0x10/0x18 irq event stamp: 3436 hardirqs last enabled at (3435): [<ffffff8010159e60>] vprintk_emit+0x230/0x31c hardirqs last disabled at (3436): [<ffffff8010081a28>] do_debug_exception+0x48/0x12c softirqs last enabled at (3428): [<ffffff8010081ee4>] __do_softirq+0x18c/0x4a0 softirqs last disabled at (3421): [<ffffff80100f4a60>] irq_exit+0xa4/0x100 ---[ end trace ba79265b58264683 ]--- phy phy-ee080200.usb-phy.11: phy poweroff failed --> -5 So far I've seen this on Salvator-X with R-Car H3 ES1.0 or M3-W, and on Salvator-XS with R-Car M3-N, but not (yet?) on H3 ES2.0. Unfortunately the issue seems to be fairly timing-sensitive, so I failed to bisect it. I have added some debug. While this didn't help me finding the cause of the above warning, it did discover another imbalance: A) Boot: phy phy-ee080200.usb-phy.7: rcar_gen3_phy_usb2_power_on: Enabling regulator (from ehci_platform_probe) B) System suspend (s2idle): phy phy-ee080200.usb-phy.7: rcar_gen3_phy_usb2_power_off: Disabling regulator (from async_suspend) Looks OK. C) System resume: phy phy-ee080200.usb-phy.7: rcar_gen3_phy_usb2_power_on: Enabling regulator phy phy-ee080200.usb-phy.6: rcar_gen3_phy_usb2_power_on: Enabling regulator (from async_resume) What's this phy-ee080200.usb-phy.6, which was never enabled before, during boot? D) System suspend (s2idle): phy phy-ee080200.usb-phy.7: rcar_gen3_phy_usb2_power_off: Disabling regulator E) System resume: phy phy-ee080200.usb-phy.6: rcar_gen3_phy_usb2_power_on: Enabling regulator phy phy-ee080200.usb-phy.7: rcar_gen3_phy_usb2_power_on: Enabling regulator I.e. phy-ee080200.usb-phy.6 keeps on being enabled during each system resume, but is never disabled Do you have a clue? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds