From c40cf7705e13d288d900e044c0a2f756e9e4909a Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 16 Apr 2019 14:53:49 -0700 Subject: usb: dwc2: optionally assert phy reset when waking up On the rk3288 USB host-only port (the one that's not the OTG-enabled port) the PHY can get into a bad state when a wakeup is asserted (not just a wakeup from full system suspend but also a wakeup from autosuspend). We can get the PHY out of its bad state by asserting its "port reset", but unfortunately that seems to assert a reset onto the USB bus so it could confuse things if we don't actually deenumerate / reenumerate the device. We can also get the PHY out of its bad state by fully resetting it using the reset from the CRU (clock reset unit), which does a more full reset. The CRU-based reset appears to actually cause devices on the bus to be removed and reinserted, which fixes the problem (albeit in a hacky way). It's unfortunate that we need to do a full re-enumeration of devices at wakeup time, but this is better than alternative of letting the bus get wedged. Signed-off-by: Douglas Anderson Signed-off-by: Yunzhi Li Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/platform.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/usb/dwc2/platform.c') diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index 9aa9682a5cd2..c01fa8ffc0c8 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -481,6 +481,15 @@ static int dwc2_driver_probe(struct platform_device *dev) hsotg->gadget_enabled = 1; } + hsotg->reset_phy_on_wake = + of_property_read_bool(dev->dev.of_node, + "snps,reset-phy-on-wake"); + if (hsotg->reset_phy_on_wake && !hsotg->phy) { + dev_warn(hsotg->dev, + "Quirk reset-phy-on-wake only supports generic PHYs\n"); + hsotg->reset_phy_on_wake = false; + } + if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL) { retval = dwc2_hcd_init(hsotg); if (retval) { -- cgit v1.2.3