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. I've tested this series atop a bit of a conglomeration of Heiko's github "somewhat stable" branch (v4.3-rc3-876-g6509232) but with Greg KH's usb-next merged in. === I've posted up a bunch of patches recently but tried to keep them in separate series where it makes sense. A summary of known patches: All patches can be found with: https://patchwork.kernel.org/patch/<ID>/ ACKed (thanks!) and not yet landed: 7453801 usb: dwc2: host: Fix ahbcfg for rk3066 7467521 usb: dwc2: host: Fix remote wakeup when not in DWC2_L2 Important, not yet reviewed: 7421171 [1/2] usb: dwc2: host: Fix missing device insertions Fixes no known issues, not yet reviewed: 7421181 [2/2] usb: dwc2: host: Clear interrupts before handling them Optimization to reduce probe time (may require simple rebase): 7348131 [1/5] usb: dwc2: Restore GUSBCFG in dwc2_get_hwparams() 7348221 [2/5] usb: dwc2: reset dwc2 core before dwc2_get_hwparams() 7348191 [3/5] CHROMIUM: usb: dwc2: Avoid double-reset at boot time 7348211 [4/5] usb: dwc2: Speed dwc2_get_hwparams() on some host-only ports 7348201 [5/5] usb: dwc2: reduce dwc2 driver probe time 7355241 usb: dwc2: Avoid more calls to dwc2_core_reset() This series: usb: dwc2: optionally assert phy "full reset" when waking up ARM: dts: rockchip: Point rk3288 dwc2 usb at the full PHY reset Coming soon: RFT: usb: dwc2: bus suspend/resume that's not hibernate Abandoned for now (can't get wakeup to work on mainline): 6727091 [REPOST,1/3] USB: Export usb_wakeup_enabled_descendants() 6727101 [REPOST,2/3] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB 6727121 [REPOST,3/3] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled Changes in v2: - Use a full PHY reset for safety; no PHY changes needed for that. - Cover letter explains outstanding patches Doug Anderson (2): usb: dwc2: optionally assert phy "full reset" when waking up ARM: dts: rockchip: Point rk3288 dwc2 usb at the full PHY reset Documentation/devicetree/bindings/usb/dwc2.txt | 7 +++++++ arch/arm/boot/dts/rk3288.dtsi | 5 +++++ drivers/usb/dwc2/core.h | 5 +++++ drivers/usb/dwc2/core_intr.c | 14 ++++++++++++++ drivers/usb/dwc2/platform.c | 13 +++++++++++++ 5 files changed, 44 insertions(+) -- 2.6.0.rc2.230.g3dd15c0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
