[PATCH] usb: dwc3: core: power on PHYs before initializing core

Felipe Balbi balbi at kernel.org
Thu Mar 8 02:43:40 PST 2018

Hi Roger,

William Wu <william.wu at rock-chips.com> writes:
> The dwc3_core_init() gets the PHYs and initializes the PHYs with
> the usb_phy_init() and phy_init() functions before initializing
> core, and power on the PHYs after core initialization is done.
> However, some platforms (e.g. Rockchip RK3399 DWC3 with Type-C
> USB3 PHY), it needs to do some special operation while power on
> the Type-C PHY before initializing DWC3 core. It's because that
> the RK3399 Type-C PHY requires to hold the DWC3 controller in
> reset state to keep the PIPE power state in P2 while configuring
> the Type-C PHY, otherwise, it may cause waiting for the PIPE ready
> timeout. In this case, if we power on the PHYs after the DWC3 core
> initialization is done, the core will be reset to uninitialized
> state after power on the PHYs.
> Fix this by powering on the PHYs before initializing core. And
> because the GUID register may also be reset in this case, so we
> need to configure the GUID register after powering on the PHYs.
> Signed-off-by: William Wu <william.wu at rock-chips.com>

does this cause any regressions for your boards?

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