Re: Correct ordering of phy_init and phy_power_on

From: Kishon Vijay Abraham I
Date: Sun Dec 20 2020 - 22:18:53 EST


Hi,

On 21/12/20 4:36 am, Ahmad Fatoum wrote:
> Hello,
>
> I just noticed that USB controller drivers differ in the order in which they
> do phy_init and phy_power_on. For example:
>
> __dwc2_lowlevel_hw_enable():
>
> ret = phy_power_on(hsotg->phy);
> if (ret == 0)
> ret = phy_init(hsotg->phy);
>
> dwc3_core_init():
>
> ret = dwc3_core_soft_reset(dwc); // internally does phy_init(dwc->usb2_generic_phy);
> /* [snip] */
> ret = phy_power_on(dwc->usb2_generic_phy);
>
>
> My initial assumption has been init -> power_on, but at least the phy-stm32-usbphyc
> (used with dwc2) is written with the assumption that exit -> power_off (and therefore
> power_on -> init). If they are swapped, disabling fails.
>
> So how was it meant to be?

It is intended to be ->init() and then ->power_on(). So ideally it
should be the way dwc3 is.

Thanks,
Kishon