Hi Paul: Thank you for replying. On 2014/12/6 3:04, Paul Zimmerman wrote: >> From: Yunzhi Li [mailto:lyz at rock-chips.com] >> Sent: Friday, December 05, 2014 4:52 AM >> >> Get PHY parameters from devicetree and power off usb PHY during >> system suspend. >> >> Signed-off-by: Yunzhi Li <lyz at rock-chips.com> >> --- >> >> drivers/usb/dwc2/gadget.c | 33 ++++++++++++--------------------- >> drivers/usb/dwc2/platform.c | 34 ++++++++++++++++++++++++++++++++++ >> 2 files changed, 46 insertions(+), 21 deletions(-) >> >> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c >> index 200168e..2601c61 100644 >> --- a/drivers/usb/dwc2/gadget.c >> +++ b/drivers/usb/dwc2/gadget.c >> [...] >> >> /* >> - * Attempt to find a generic PHY, then look for an old style >> - * USB PHY, finally fall back to pdata >> + * If platform probe couldn't find a generic PHY or an old style >> + * USB PHY, fall back to pdata >> */ >> - phy = devm_phy_get(dev, "usb2-phy"); >> - if (IS_ERR(phy)) { >> - uphy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2); >> - if (IS_ERR(uphy)) { >> - /* Fallback for pdata */ >> - plat = dev_get_platdata(dev); >> - if (!plat) { >> - dev_err(dev, >> - "no platform data or transceiver defined\n"); >> - return -EPROBE_DEFER; >> - } >> - hsotg->plat = plat; >> - } else >> - hsotg->uphy = uphy; >> - } else { >> - hsotg->phy = phy; >> + if (IS_ERR_OR_NULL(hsotg->phy) && IS_ERR_OR_NULL(hsotg->uphy)) { >> + plat = dev_get_platdata(dev); >> + if (!plat) { >> + dev_err(dev, >> + "no platform data or transceiver defined\n"); >> + return -EPROBE_DEFER; >> + } >> + hsotg->plat = plat; >> + } else if (hsotg->phy) { > You have changed the behavior here. Previously, the driver would work > even if there were no phys or pdata defined. Now it will return > -EPROBE_DEFER instead. Are you sure that won't break any existing > platforms? > I don't really catch your meaning. Could you please point out where is the difference? Thanks . In previous version, if there were no phy or usb_phy defined, devm_phy_get() and devm_usb_get_phy() both failed, then driver falls back to find pdata, if no pdata defined dev_get_platdata() returns NULL, then dwc2_gadget_init returns -EPROBE_DEFER and the dwc2_driver_probe fail. So I think, for the dwc2 driver without my patch, when CONFIG_USB_DWC2_PERIPHERAL or CONFIG_USB_DWC2_DUAL_ROLE selected, if there were no phys or pdata defined, the driver probe will also return -EPROBE_DEFER. And when only CONFIG_USB_DWC2_HOST selected, the previous version driver didn't care any thing about phy, in my patch it will try to find a phy when platform driver probe, but do not fail probe if there isn't a phy node.
