Hi, > From: Alan Stern, Sent: Wednesday, November 29, 2017 12:07 AM > > On Tue, 28 Nov 2017, Yoshihiro Shimoda wrote: > > > Hi Geert-san, > > > > > From: Geert Uytterhoeven, Sent: Tuesday, November 28, 2017 7:58 PM > > > > > > Hi Rafael, Shimoda-san, > > > > > > On Sun, Nov 12, 2017 at 1:27 AM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> <snip> > > > JFTR, this triggered before during system resume on e.g. Salvator-XS with > > > R-Car H3: > > > > > > ohci-platform ee080000.usb: runtime PM trying to suspend device > > > but active child > > > phy_rcar_gen3_usb2 ee080200.usb-phy: runtime PM trying to suspend > > > device but active child > > > ohci-platform ee0c0000.usb: runtime PM trying to suspend device > > > but active child > > > ohci-platform ee0a0000.usb: runtime PM trying to suspend device > > > but active child > > > phy_rcar_gen3_usb2 ee0c0200.usb-phy: runtime PM trying to suspend > > > device but active child > > > phy_rcar_gen3_usb2 ee0a0200.usb-phy: runtime PM trying to suspend > > > device but active child > > > > > > so this was an existing issue with USB before. > > > > Thank you for the report! > > I know that, but since this didn't cause any trouble until now, > > I postponed to investigate the issue... But, I investigate it today. > > I don't find the root cause yet. However, it seems related to usb host and/or usb core. > > --> USB host related devices' child_count will be 1 in suspend timing. > > --> I guess remote wakeup feature is enabled? But, I don't find the point yet. > > > > The renesas_usbhs also uses the phy_rcar_gen3_usb2 driver. I'm so sorry, but this is mistake. The renesas_usbhs doesn't use the phy_rcar_gen3_usb2 driver. So, > > --> If I only used the renesas_usbhs driver (in other words, I don't install > > [eo]hci-{hcd,platform} drivers), the issue disappeared. > > --> So, I think the phy_rcar_gen3_usb2 driver doesn't cause this issue. > > (But, it is possible to be related though.) They are also mistake. > > I'll continue to investigate this issue tomorrow. > > Does the phy_rcar_gen3_usb2 driver use runtime PM? Yes, the phy_rcar_gen3_usb2 uses runtime PM. > It looks like the > phy device somehow gets enabled for runtime PM when it shouldn't be. I also think that now. I don't find why for now, but the usage_count of a phy device was not 1 just before suspend. (This "a phy device" means the child of ee0a0200.usb-phy device.) > (And by the way, what device is the child of ee0a0200.usb-phy?) It's a phy device: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/phy/phy-core.c?h=v4.15-rc1#n773 Best regards, Yoshihiro Shimoda > Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html