diff options
| author | Douglas Anderson <dianders@chromium.org> | 2019-04-16 23:53:49 +0200 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2019-05-03 08:13:47 +0200 |
| commit | c40cf7705e13d288d900e044c0a2f756e9e4909a (patch) | |
| tree | 31ab9133f03c69cda3587744766a8ce59a72eddb /drivers/usb/dwc2/platform.c | |
| parent | dt-bindings: usb: dwc2: Document quirk to reset PHY upon wakeup (diff) | |
| download | linux-c40cf7705e13d288d900e044c0a2f756e9e4909a.tar.xz linux-c40cf7705e13d288d900e044c0a2f756e9e4909a.zip | |
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 <dianders@chromium.org>
Signed-off-by: Yunzhi Li <lyz@rock-chips.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/dwc2/platform.c')
| -rw-r--r-- | drivers/usb/dwc2/platform.c | 9 |
1 files changed, 9 insertions, 0 deletions
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) { |