On 8/15/2016 6:11 PM, Randy Li wrote:
>
>
> On 08/16/2016 06:19 AM, John Youn wrote:
>> On 7/19/2016 5:06 AM, Randy Li wrote:
>>> From: Doug Anderson <dianders@xxxxxxxxxxxx>
>>>
>>> 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). The problem is caused by a design fault in IC, Rockchip
>>> have confirmed it and fix this problem in the future IC model.
>>>
>>> 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), 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: Douglas Anderson <dianders@xxxxxxxxxxxx>
>>> Signed-off-by: Yunzhi Li <lyz@xxxxxxxxxxxxxx>
>>> Reviewed-by: Randy Li <randy.li@xxxxxxxxxxxxxx>
>>> ---
>>> Documentation/devicetree/bindings/usb/dwc2.txt | 7 +++++++
>>> drivers/usb/dwc2/core.h | 5 +++++
>>> drivers/usb/dwc2/core_intr.c | 14 ++++++++++++++
>>> drivers/usb/dwc2/platform.c | 13 +++++++++++++
>>> 4 files changed, 39 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/dwc2.txt b/Documentation/devicetree/bindings/usb/dwc2.txt
>>> index 20a68bf..40c63ae 100644
>>> --- a/Documentation/devicetree/bindings/usb/dwc2.txt
>>> +++ b/Documentation/devicetree/bindings/usb/dwc2.txt
>>> @@ -20,6 +20,13 @@ Refer to clk/clock-bindings.txt for generic clock consumer properties
>>> Optional properties:
>>> - phys: phy provider specifier
>>> - phy-names: shall be "usb2-phy"
>>> +- snps,need-phy-full-reset-on-wake: if present indicates that we need to reset
>>> + the PHY when we detect a wakeup due to a hardware errata. If present you
>>> + must specify a "phy-full-reset" reset.
>>> +
>>> +Resets:
>>> +- phy-full-reset (optional): Fully resets the PHY (Only used by rk3288 Soc).
>>> +
>>> Refer to phy/phy-bindings.txt for generic phy consumer properties
>>> - dr_mode: shall be one of "host", "peripheral" and "otg"
>>> Refer to usb/generic.txt
>>> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
>>> index dec0b21..951abe0 100644
>>> --- a/drivers/usb/dwc2/core.h
>>> +++ b/drivers/usb/dwc2/core.h
>>> @@ -719,8 +719,11 @@ struct dwc2_hregs_backup {
>>> * @hcd_enabled Host mode sub-driver initialization indicator.
>>> * @gadget_enabled Peripheral mode sub-driver initialization indicator.
>>> * @ll_hw_enabled Status of low-level hardware resources.
>>> + * @need_phy_full_reset_on_wake: Quirk saying that we should assert
>>> + * phy_full_reset on a remote wakeup.
>>> * @phy: The otg phy transceiver structure for phy control.
>>> * @uphy: The otg phy transceiver structure for old USB phy control.
>>> + * @phy_full_reset: Reset control for the PHY's "full reset".
>>> * @plat: The platform specific configuration data. This can be removed once
>>> * all SoCs support usb transceiver.
>>> * @supplies: Definition of USB power supplies
>>> @@ -853,9 +856,11 @@ struct dwc2_hsotg {
>>> unsigned int hcd_enabled:1;
>>> unsigned int gadget_enabled:1;
>>> unsigned int ll_hw_enabled:1;
>>> + unsigned int need_phy_full_reset_on_wake:1;
>>>
>>> struct phy *phy;
>>> struct usb_phy *uphy;
>>> + struct reset_control *phy_full_reset;
>>> struct dwc2_hsotg_plat *plat;
>>> struct regulator_bulk_data supplies[ARRAY_SIZE(dwc2_hsotg_supply_names)];
>>> u32 phyif;
>>> diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
>>> index d85c5c9..53d8327 100644
>>> --- a/drivers/usb/dwc2/core_intr.c
>>> +++ b/drivers/usb/dwc2/core_intr.c
>>> @@ -45,6 +45,7 @@
>>> #include <linux/dma-mapping.h>
>>> #include <linux/io.h>
>>> #include <linux/slab.h>
>>> +#include <linux/reset.h>
>>> #include <linux/usb.h>
>>>
>>> #include <linux/usb/hcd.h>
>>> @@ -379,6 +380,19 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
>>> /* Restart the Phy Clock */
>>> pcgcctl &= ~PCGCTL_STOPPCLK;
>>> dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
>>> +
>>> + /*
>>> + * If we've got this quirk then the PHY is stuck upon
>>> + * wakeup. Assert reset. This will propagate out and
>>> + * eventually we'll re-enumerate the device. Not great
>>> + * but the best we can do.
>>> + */
>>> + if (hsotg->need_phy_full_reset_on_wake) {
>>> + reset_control_assert(hsotg->phy_full_reset);
>>> + udelay(50);
>>> + reset_control_deassert(hsotg->phy_full_reset);
>>> + }
>>> +
>>> 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 fc6f525..d8894a1 100644
>>> --- a/drivers/usb/dwc2/platform.c
>>> +++ b/drivers/usb/dwc2/platform.c
>>> @@ -45,6 +45,7 @@
>>> #include <linux/platform_device.h>
>>> #include <linux/phy/phy.h>
>>> #include <linux/platform_data/s3c-hsotg.h>
>>> +#include <linux/reset.h>
>>>
>>> #include <linux/usb/of.h>
>>>
>>> @@ -529,6 +530,18 @@ static int dwc2_driver_probe(struct platform_device *dev)
>>> dev_dbg(&dev->dev, "mapped PA %08lx to VA %p\n",
>>> (unsigned long)res->start, hsotg->regs);
>>>
>>> + hsotg->need_phy_full_reset_on_wake =
>>> + of_property_read_bool(dev->dev.of_node,
>>> + "snps,need-phy-full-reset-on-wake");
>>> + hsotg->phy_full_reset = devm_reset_control_get(hsotg->dev,
>>> + "phy-full-reset");
>>> + if (IS_ERR(hsotg->phy_full_reset) &&
>>> + hsotg->need_phy_full_reset_on_wake) {
>>
>> Should use the devm_reset_control_get_optional() variant so that we
>> can check whether it is a legitimate error, or the PHY is not
>> specified or !CONFIG_OF.
> I see.
Just a correction, I meant in case the reset controller is unspecified
or !CONFIG_RESET_CONTROLLER.
>>
>>> + dev_warn(hsotg->dev, "Missing phy full reset (%ld); skipping\n",
>>> + PTR_ERR(hsotg->phy_full_reset));
>>> + hsotg->need_phy_full_reset_on_wake = false;
>>> + }
>>> +
>>
>> Also this code can go into the dwc2_lowlevel_hw_init() function so as
>> not to clutter up the probe() function futher.
>>
>> A similar patch adding a reset was submitted by Dinh which you can use
>> as a reference:
>>
>> http://marc.info/?l=linux-usb&m=147085447403019&w=2
>
> I am a little busy recently, but I would submit a new version in this week.
Ok sure.
Regards,
John
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