Hi Chunfeng,

On 10/19/2016 04:28 AM, Chunfeng Yun wrote:

These patches introduce the MediaTek USB3 dual-role controller
driver.

The driver can be configured as Dual-Role Device (DRD),
Peripheral Only and Host Only (xHCI) modes. It works well
with Mass Storage, RNDIS and g_zero on FS/HS and SS. And it is
tested on MT8173 platform which only contains USB2.0 device IP,
and on MT6290 platform which contains USB3.0 device IP.

Change in v7:
1. split dual-role driver into four patchs
2. remove QMU done tasklet
3. add a bool in xhci_hcd_mtk to signal absence of IPPC

Change in v6:
1. handle endianness of GPD and SETUP data
2. remove dummy error log and return suitable error number
3. cancel delay work when deregiseter driver

Change in v5:
1. modify some comments
2. rename some unsuitable variables
3. add reg-names property for host node
4. add USB_MTU3_DEBUG to control debug messages

Change in v4:
1. fix build errors on non-mediatek platforms
2. provide manual dual-role switch via debugfs instead of sysfs

Change in v3:
1. fix some typo error
2. rename mtu3.txt to mt8173-mtu3.txt

Change in v2:
1. modify binding docs according to suggestions
2. modify some comments and remove some dummy blank lines
3. fix memory leakage


Chunfeng Yun (8):
  dt-bindings: mt8173-xhci: support host side of dual-role mode
  dt-bindings: mt8173-mtu3: add devicetree bindings
  usb: xhci-mtk: make IPPC register optional
  usb: Add MediaTek USB3 DRD driver
  usb: mtu3: Super-Speed Peripheral mode support
  usb: mtu3: host only mode support
  usb: mtu3: dual-role mode support
  arm64: dts: mediatek: add USB3 DRD driver

I tried the driver with my mt8173-evb, but wasn't able to get USB 
working (no usb stick detected when adding to the usb port).

# dmesg |grep mtu
[    0.428420] mtu3 11271000.usb: failed to get vusb33
[    0.510570] mtu3 11271000.usb: failed to get vbus
[    0.592103] mtu3 11271000.usb: failed to get vbus


Relevant config options:
CONFIG_USB_MTU3=y
CONFIG_USB_MTU3_HOST=y
CONFIG_USB_MTU3_DEBUG=y
CONFIG_PHY_MT65XX_USB3=y


Looks like an error in the device tree. I can see that the mt6397 
regulater get's initialized *after* the mtu3 driver:
[    0.505166] mt6397-regulator mt6397-regulator: Chip ID = 0x4097

Not sure if this is related.
Any idea whats going wrong here?

Cheers,
Matthias