Date:   Tue, 6 Dec 2016 20:00:29 +0800
From:   Ayaka <ayaka@...lik.info>
To:     John Youn <John.Youn@...opsys.com>
Cc:     "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "kishon@...com" <kishon@...com>,
        "felipe.balbi@...ux.intel.com" <felipe.balbi@...ux.intel.com>,
        "mark.rutland@....com" <mark.rutland@....com>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "heiko@...ech.de" <heiko@...ech.de>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "randy.li@...k-chips.com" <randy.li@...k-chips.com>
Subject: Re: [PATCH v9 1/2] usb: dwc2: assert phy reset when waking up in rk3288 platform

Hello John
  I still waiting them be merged, but I still can't find it at next-20161206.

從我的 iPad 傳送

> John Youn <John.Youn@...opsys.com> 於 2016年10月25日 上午9:30 寫道：
> 
>> On 10/23/2016 2:33 AM, ayaka wrote:
>> 
>> 
>>> On 10/22/2016 03:27 AM, John Youn wrote:
>>>> On 10/20/2016 11:38 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@...lik.info>
>>>> ---
>>>>  drivers/usb/dwc2/core.h      |  1 +
>>>>  drivers/usb/dwc2/core_intr.c | 11 +++++++++++
>>>>  drivers/usb/dwc2/platform.c  |  9 +++++++++
>>>>  3 files changed, 21 insertions(+)
>>>> 
>>>> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
>>>> index 2a21a04..e91ddbc 100644
>>>> --- a/drivers/usb/dwc2/core.h
>>>> +++ b/drivers/usb/dwc2/core.h
>>>> @@ -859,6 +859,7 @@ struct dwc2_hsotg {
>>>>      unsigned int ll_hw_enabled:1;
>>>> 
>>>>      struct phy *phy;
>>>> +    struct work_struct phy_rst_work;
>>>>      struct usb_phy *uphy;
>>>>      struct dwc2_hsotg_plat *plat;
>>>>      struct regulator_bulk_data supplies[ARRAY_SIZE(dwc2_hsotg_supply_names)];
>>>> diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
>>>> index d85c5c9..c3d2168 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 +380,16 @@ 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"))
>>>> +                schedule_work(&hsotg->phy_rst_work);
>>>> +
>>>>              mod_timer(&hsotg->wkp_timer,
>>>>                    jiffies + msecs_to_jiffies(71));
>>>>          } else {
>>>> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
>>>> index 8e1728b..65953cf 100644
>>>> --- a/drivers/usb/dwc2/platform.c
>>>> +++ b/drivers/usb/dwc2/platform.c
>>>> @@ -366,6 +366,14 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
>>>>      return ret;
>>>>  }
>>>> 
>>>> +/* Only used to reset usb phy at interrupter runtime */
>>>> +static void dwc2_reset_phy_work(struct work_struct *data)
>>>> +{
>>>> +    struct dwc2_hsotg *hsotg = container_of(data, struct dwc2_hsotg,
>>>> +            phy_rst_work);
>>>> +    phy_reset(hsotg->phy);
>>>> +}
>>>> +
>>>>  static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
>>>>  {
>>>>      int i, ret;
>>>> @@ -410,6 +418,7 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
>>>>              return ret;
>>>>          }
>>>>      }
>>>> +    INIT_WORK(&hsotg->phy_rst_work, dwc2_reset_phy_work);
>>>> 
>>>>      if (!hsotg->phy) {
>>>>          hsotg->uphy = devm_usb_get_phy(hsotg->dev, USB_PHY_TYPE_USB2);
>>>> 
>>> Hi Randy,
>>> 
>>> This fails compile if CONFIG_GENERIC_PHY is disabled. I think you need
>>> to make a fix to your phy_reset patch first.
>> In the last time, cac18ecb6f44b11bc303d7afbae3887b27938fa4 have not been 
>> merged, I though the
>> [PATCH v8 1/3] phy: Add reset callback for not generic phy have been 
>> merged before that. when the rebase abandon it.
>> Should re-send that patch? As the mainline have not been affected, could 
>> you arrange a squash for it?
> 
> Hi Randy,
> 
> Can you resend the fix to Kishon?
> 
> The phy_reset patch landed in 4.9-rc so I think he should take the fix
> for the next -rc. After that we can send the dwc2 change through
> Felipe.
> 
> Regards,
> John

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