On 9/6/2016 6:19 PM, Ayaka wrote: > > > 從我的 iPad 傳送 > >> John Youn <John.Youn@xxxxxxxxxxxx> 於 2016年9月7日 上午2:54 寫道: >> >>> On 9/5/2016 10:15 PM, Kishon Vijay Abraham I wrote: >>> Hi, >>> >>>> On Sunday 04 September 2016 03:25 AM, Randy Li wrote: >>>> 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) in chip, 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. >>>> >>>> Signed-off-by: Randy Li <ayaka@xxxxxxxxxxx> >>>> --- >>>> drivers/usb/dwc2/core_intr.c | 12 ++++++++++++ >>>> 1 file changed, 12 insertions(+) >>>> >>>> diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c >>>> index d85c5c9..08485b7 100644 >>>> --- a/drivers/usb/dwc2/core_intr.c >>>> +++ b/drivers/usb/dwc2/core_intr.c >>>> @@ -345,6 +345,7 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg) >>>> static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) >>>> { >>>> int ret; >>>> + struct device_node *np = hsotg->dev->of_node; >>>> >>>> /* Clear interrupt */ >>>> dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS); >>>> @@ -379,6 +380,17 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) >>>> /* Restart the Phy Clock */ >>>> pcgcctl &= ~PCGCTL_STOPPCLK; >>>> dwc2_writel(pcgcctl, hsotg->regs + PCGCTL); >>>> + >>>> + /* >>>> + * It is a quirk in Rockchip RK3288, causing by >>>> + * a hardware bug. This will propagate out and >>>> + * eventually we'll re-enumerate the device. >>>> + * Not great but the best we can do >>>> + */ >>>> + if (of_device_is_compatible(np, "rockchip,rk3288-usb") >>>> + && (NULL != hsotg->phy->ops->reset)) >>>> + hsotg->phy->ops->reset(hsotg->phy); >>> >>> never call the phy ops directly from the controller driver. It has to be >>> protected as well. >> >> It looks like we should be calling an API function instead, correct? >> > Could you give me a example for the wrapper of phy ops? Check these files: * include/linux/phy/phy.h * drivers/phy/phy-core.c Search for "phy_set_mode". I'm thinking there should be a "phy_reset" API function which calls the phy->ops->reset in a similar manner. With the same runtime checks and stub function if CONFIG_GENERIC_PHY is not enabled. Regards, John -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html