diff mbox

[4/4] usb: dwc3: core: Support the dwc3 host suspend/resume

Message ID 9cca1b5a0487676a4fa912e957a03642a330c20a.1468571634.git.baolin.wang@linaro.org
State New
Headers show

Commit Message

(Exiting) Baolin Wang July 15, 2016, 9:13 a.m. UTC
For some mobile devices with strict power management, we also want to suspend
the host when the slave is detached for power saving.

Thus we add the host suspend/resume functions to support this requirement, and
we also should enable the 'XHCI_SLOW_SUSPEND' quirk for extraordinary delay when
suspending the xhci.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

---
 drivers/usb/dwc3/Kconfig |    7 +++++++
 drivers/usb/dwc3/core.c  |   25 ++++++++++++++++++++++++-
 drivers/usb/dwc3/core.h  |   15 +++++++++++++++
 drivers/usb/dwc3/host.c  |   32 ++++++++++++++++++++++++++++++++
 4 files changed, 78 insertions(+), 1 deletion(-)

-- 
1.7.9.5

Comments

(Exiting) Baolin Wang Aug. 18, 2016, 8:59 a.m. UTC | #1
Hi Felipe,

On 18 August 2016 at 15:33, Felipe Balbi <balbi@kernel.org> wrote:
>

> Hi,

>

> Baolin Wang <baolin.wang@linaro.org> writes:

>> For some mobile devices with strict power management, we also want to suspend

>> the host when the slave is detached for power saving.

>>

>> Thus we add the host suspend/resume functions to support this requirement, and

>> we also should enable the 'XHCI_SLOW_SUSPEND' quirk for extraordinary delay when

>> suspending the xhci.

>>

>> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

>> ---

>>  drivers/usb/dwc3/Kconfig |    7 +++++++

>>  drivers/usb/dwc3/core.c  |   25 ++++++++++++++++++++++++-

>>  drivers/usb/dwc3/core.h  |   15 +++++++++++++++

>>  drivers/usb/dwc3/host.c  |   32 ++++++++++++++++++++++++++++++++

>>  4 files changed, 78 insertions(+), 1 deletion(-)

>>

>> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig

>> index a64ce1c..725d2bd 100644

>> --- a/drivers/usb/dwc3/Kconfig

>> +++ b/drivers/usb/dwc3/Kconfig

>> @@ -45,6 +45,13 @@ config USB_DWC3_DUAL_ROLE

>>         This is the default mode of working of DWC3 controller where

>>         both host and gadget features are enabled.

>>

>> +config USB_DWC3_HOST_SUSPEND

>> +     bool "Choose if the host (xhci) can be suspend/resume"

>> +     depends on USB_DWC3_HOST=y || USB_DWC3_DUAL_ROLE=y

>> +     help

>> +       We can suspend the host when the slave is detached for power saving,

>> +       and resume the host when one slave is attached.

>> +

>>  endchoice

>>

>>  comment "Platform Glue Driver Support"

>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c

>> index 1485480..5140b4d 100644

>> --- a/drivers/usb/dwc3/core.c

>> +++ b/drivers/usb/dwc3/core.c

>> @@ -1103,15 +1103,27 @@ static int dwc3_remove(struct platform_device *pdev)

>>  static int dwc3_suspend_common(struct dwc3 *dwc)

>>  {

>>       unsigned long   flags;

>> +     int             ret;

>>

>>       switch (dwc->dr_mode) {

>>       case USB_DR_MODE_PERIPHERAL:

>> +             spin_lock_irqsave(&dwc->lock, flags);

>> +             dwc3_gadget_suspend(dwc);

>> +             spin_unlock_irqrestore(&dwc->lock, flags);

>> +             break;

>>       case USB_DR_MODE_OTG:

>> +             ret = dwc3_host_suspend(dwc);

>> +             if (ret)

>> +                     return ret;

>> +

>>               spin_lock_irqsave(&dwc->lock, flags);

>>               dwc3_gadget_suspend(dwc);

>>               spin_unlock_irqrestore(&dwc->lock, flags);

>>               break;

>>       case USB_DR_MODE_HOST:

>> +             ret = dwc3_host_suspend(dwc);

>> +             if (ret)

>> +                     return ret;

>>       default:

>>               /* do nothing */

>>               break;

>> @@ -1133,12 +1145,23 @@ static int dwc3_resume_common(struct dwc3 *dwc)

>>

>>       switch (dwc->dr_mode) {

>>       case USB_DR_MODE_PERIPHERAL:

>> +             spin_lock_irqsave(&dwc->lock, flags);

>> +             dwc3_gadget_resume(dwc);

>> +             spin_unlock_irqrestore(&dwc->lock, flags);

>> +             break;

>>       case USB_DR_MODE_OTG:

>> +             ret = dwc3_host_resume(dwc);

>> +             if (ret)

>> +                     return ret;

>> +

>>               spin_lock_irqsave(&dwc->lock, flags);

>>               dwc3_gadget_resume(dwc);

>>               spin_unlock_irqrestore(&dwc->lock, flags);

>> -             /* FALLTHROUGH */

>> +             break;

>>       case USB_DR_MODE_HOST:

>> +             ret = dwc3_host_resume(dwc);

>> +             if (ret)

>> +                     return ret;

>>       default:

>>               /* do nothing */

>>               break;

>> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h

>> index 45d6de5..0ba203e 100644

>> --- a/drivers/usb/dwc3/core.h

>> +++ b/drivers/usb/dwc3/core.h

>> @@ -1177,4 +1177,19 @@ static inline void dwc3_ulpi_exit(struct dwc3 *dwc)

>>  { }

>>  #endif

>>

>> +#if IS_ENABLED(USB_DWC3_HOST_SUSPEND)

>> +int dwc3_host_suspend(struct dwc3 *dwc);

>> +int dwc3_host_resume(struct dwc3 *dwc);

>> +#else

>> +static inline int dwc3_host_suspend(struct dwc3 *dwc)

>> +{

>> +     return 0;

>> +}

>> +

>> +static inline int dwc3_host_resume(struct dwc3 *dwc)

>> +{

>> +     return 0;

>> +}

>> +#endif

>> +

>>  #endif /* __DRIVERS_USB_DWC3_CORE_H */

>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c

>> index 2e960ed..2ec3eff 100644

>> --- a/drivers/usb/dwc3/host.c

>> +++ b/drivers/usb/dwc3/host.c

>> @@ -17,8 +17,11 @@

>>

>>  #include <linux/platform_device.h>

>>  #include <linux/usb/xhci_pdriver.h>

>> +#include <linux/usb.h>

>> +#include <linux/usb/hcd.h>

>>

>>  #include "core.h"

>> +#include "../host/xhci.h"

>>

>>  int dwc3_host_init(struct dwc3 *dwc)

>>  {

>> @@ -91,6 +94,8 @@ int dwc3_host_init(struct dwc3 *dwc)

>>       memset(&pdata, 0, sizeof(pdata));

>>

>>       pdata.usb3_lpm_capable = dwc->usb3_lpm_capable;

>> +     /* dwc3 controller need an extraordinary delay when suspending xhci. */

>> +     pdata.usb3_slow_suspend = 1;

>>

>>       ret = platform_device_add_data(xhci, &pdata, sizeof(pdata));

>>       if (ret) {

>> @@ -128,3 +133,30 @@ void dwc3_host_exit(struct dwc3 *dwc)

>>                         dev_name(&dwc->xhci->dev));

>>       platform_device_unregister(dwc->xhci);

>>  }

>> +

>> +int dwc3_host_suspend(struct dwc3 *dwc)

>> +{

>> +     struct usb_hcd *hcd = dev_get_drvdata(&dwc->xhci->dev);

>> +     struct xhci_hcd *xhci = hcd_to_xhci(hcd);

>> +     int ret, cnt = 20;

>> +

>> +try_again:

>> +      /* We should wait for xhci bus has been into suspend mode firstly. */

>> +     ret = xhci_suspend(xhci, device_may_wakeup(&dwc->xhci->dev));

>> +     if (ret && --cnt > 0) {

>> +             dev_warn(dwc->dev, "xhci suspend failed %d, try again...\n",

>> +                      ret);

>> +             msleep(200);

>> +             goto try_again;

>> +     }

>> +

>> +     return ret;

>> +}

>> +

>> +int dwc3_host_resume(struct dwc3 *dwc)

>> +{

>> +     struct usb_hcd *hcd = dev_get_drvdata(&dwc->xhci->dev);

>> +     struct xhci_hcd *xhci = hcd_to_xhci(hcd);

>> +

>> +     return xhci_resume(xhci, 0);

>> +}

>

> This is wrong. XHCI is a child of dwc3, when dwc3 suspends,

> xhci_supend() has already been called. Why isn't it called for you?


xhci-plat.c did not set the runtime PM callbacks, how can we issued
xhci_supend() by runtime PM from dwc3?

-- 
Baolin.wang
Best Regards
(Exiting) Baolin Wang Aug. 18, 2016, 12:52 p.m. UTC | #2
Hi Felipe,

On 18 August 2016 at 20:25, Felipe Balbi <balbi@kernel.org> wrote:
>

> Hi,

>

> Baolin Wang <baolin.wang@linaro.org> writes:

>> Hi Felipe,

>>

>> On 18 August 2016 at 15:33, Felipe Balbi <balbi@kernel.org> wrote:

>>>

>>> Hi,

>>>

>>> Baolin Wang <baolin.wang@linaro.org> writes:

>>>> For some mobile devices with strict power management, we also want to suspend

>>>> the host when the slave is detached for power saving.

>>>>

>>>> Thus we add the host suspend/resume functions to support this requirement, and

>>>> we also should enable the 'XHCI_SLOW_SUSPEND' quirk for extraordinary delay when

>>>> suspending the xhci.

>>>>

>>>> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

>>>> ---

>>>>  drivers/usb/dwc3/Kconfig |    7 +++++++

>>>>  drivers/usb/dwc3/core.c  |   25 ++++++++++++++++++++++++-

>>>>  drivers/usb/dwc3/core.h  |   15 +++++++++++++++

>>>>  drivers/usb/dwc3/host.c  |   32 ++++++++++++++++++++++++++++++++

>>>>  4 files changed, 78 insertions(+), 1 deletion(-)

>>>>

>>>> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig

>>>> index a64ce1c..725d2bd 100644

>>>> --- a/drivers/usb/dwc3/Kconfig

>>>> +++ b/drivers/usb/dwc3/Kconfig

>>>> @@ -45,6 +45,13 @@ config USB_DWC3_DUAL_ROLE

>>>>         This is the default mode of working of DWC3 controller where

>>>>         both host and gadget features are enabled.

>>>>

>>>> +config USB_DWC3_HOST_SUSPEND

>>>> +     bool "Choose if the host (xhci) can be suspend/resume"

>>>> +     depends on USB_DWC3_HOST=y || USB_DWC3_DUAL_ROLE=y

>>>> +     help

>>>> +       We can suspend the host when the slave is detached for power saving,

>>>> +       and resume the host when one slave is attached.

>>>> +

>>>>  endchoice

>>>>

>>>>  comment "Platform Glue Driver Support"

>>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c

>>>> index 1485480..5140b4d 100644

>>>> --- a/drivers/usb/dwc3/core.c

>>>> +++ b/drivers/usb/dwc3/core.c

>>>> @@ -1103,15 +1103,27 @@ static int dwc3_remove(struct platform_device *pdev)

>>>>  static int dwc3_suspend_common(struct dwc3 *dwc)

>>>>  {

>>>>       unsigned long   flags;

>>>> +     int             ret;

>>>>

>>>>       switch (dwc->dr_mode) {

>>>>       case USB_DR_MODE_PERIPHERAL:

>>>> +             spin_lock_irqsave(&dwc->lock, flags);

>>>> +             dwc3_gadget_suspend(dwc);

>>>> +             spin_unlock_irqrestore(&dwc->lock, flags);

>>>> +             break;

>>>>       case USB_DR_MODE_OTG:

>>>> +             ret = dwc3_host_suspend(dwc);

>>>> +             if (ret)

>>>> +                     return ret;

>>>> +

>>>>               spin_lock_irqsave(&dwc->lock, flags);

>>>>               dwc3_gadget_suspend(dwc);

>>>>               spin_unlock_irqrestore(&dwc->lock, flags);

>>>>               break;

>>>>       case USB_DR_MODE_HOST:

>>>> +             ret = dwc3_host_suspend(dwc);

>>>> +             if (ret)

>>>> +                     return ret;

>>>>       default:

>>>>               /* do nothing */

>>>>               break;

>>>> @@ -1133,12 +1145,23 @@ static int dwc3_resume_common(struct dwc3 *dwc)

>>>>

>>>>       switch (dwc->dr_mode) {

>>>>       case USB_DR_MODE_PERIPHERAL:

>>>> +             spin_lock_irqsave(&dwc->lock, flags);

>>>> +             dwc3_gadget_resume(dwc);

>>>> +             spin_unlock_irqrestore(&dwc->lock, flags);

>>>> +             break;

>>>>       case USB_DR_MODE_OTG:

>>>> +             ret = dwc3_host_resume(dwc);

>>>> +             if (ret)

>>>> +                     return ret;

>>>> +

>>>>               spin_lock_irqsave(&dwc->lock, flags);

>>>>               dwc3_gadget_resume(dwc);

>>>>               spin_unlock_irqrestore(&dwc->lock, flags);

>>>> -             /* FALLTHROUGH */

>>>> +             break;

>>>>       case USB_DR_MODE_HOST:

>>>> +             ret = dwc3_host_resume(dwc);

>>>> +             if (ret)

>>>> +                     return ret;

>>>>       default:

>>>>               /* do nothing */

>>>>               break;

>>>> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h

>>>> index 45d6de5..0ba203e 100644

>>>> --- a/drivers/usb/dwc3/core.h

>>>> +++ b/drivers/usb/dwc3/core.h

>>>> @@ -1177,4 +1177,19 @@ static inline void dwc3_ulpi_exit(struct dwc3 *dwc)

>>>>  { }

>>>>  #endif

>>>>

>>>> +#if IS_ENABLED(USB_DWC3_HOST_SUSPEND)

>>>> +int dwc3_host_suspend(struct dwc3 *dwc);

>>>> +int dwc3_host_resume(struct dwc3 *dwc);

>>>> +#else

>>>> +static inline int dwc3_host_suspend(struct dwc3 *dwc)

>>>> +{

>>>> +     return 0;

>>>> +}

>>>> +

>>>> +static inline int dwc3_host_resume(struct dwc3 *dwc)

>>>> +{

>>>> +     return 0;

>>>> +}

>>>> +#endif

>>>> +

>>>>  #endif /* __DRIVERS_USB_DWC3_CORE_H */

>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c

>>>> index 2e960ed..2ec3eff 100644

>>>> --- a/drivers/usb/dwc3/host.c

>>>> +++ b/drivers/usb/dwc3/host.c

>>>> @@ -17,8 +17,11 @@

>>>>

>>>>  #include <linux/platform_device.h>

>>>>  #include <linux/usb/xhci_pdriver.h>

>>>> +#include <linux/usb.h>

>>>> +#include <linux/usb/hcd.h>

>>>>

>>>>  #include "core.h"

>>>> +#include "../host/xhci.h"

>>>>

>>>>  int dwc3_host_init(struct dwc3 *dwc)

>>>>  {

>>>> @@ -91,6 +94,8 @@ int dwc3_host_init(struct dwc3 *dwc)

>>>>       memset(&pdata, 0, sizeof(pdata));

>>>>

>>>>       pdata.usb3_lpm_capable = dwc->usb3_lpm_capable;

>>>> +     /* dwc3 controller need an extraordinary delay when suspending xhci. */

>>>> +     pdata.usb3_slow_suspend = 1;

>>>>

>>>>       ret = platform_device_add_data(xhci, &pdata, sizeof(pdata));

>>>>       if (ret) {

>>>> @@ -128,3 +133,30 @@ void dwc3_host_exit(struct dwc3 *dwc)

>>>>                         dev_name(&dwc->xhci->dev));

>>>>       platform_device_unregister(dwc->xhci);

>>>>  }

>>>> +

>>>> +int dwc3_host_suspend(struct dwc3 *dwc)

>>>> +{

>>>> +     struct usb_hcd *hcd = dev_get_drvdata(&dwc->xhci->dev);

>>>> +     struct xhci_hcd *xhci = hcd_to_xhci(hcd);

>>>> +     int ret, cnt = 20;

>>>> +

>>>> +try_again:

>>>> +      /* We should wait for xhci bus has been into suspend mode firstly. */

>>>> +     ret = xhci_suspend(xhci, device_may_wakeup(&dwc->xhci->dev));

>>>> +     if (ret && --cnt > 0) {

>>>> +             dev_warn(dwc->dev, "xhci suspend failed %d, try again...\n",

>>>> +                      ret);

>>>> +             msleep(200);

>>>> +             goto try_again;

>>>> +     }

>>>> +

>>>> +     return ret;

>>>> +}

>>>> +

>>>> +int dwc3_host_resume(struct dwc3 *dwc)

>>>> +{

>>>> +     struct usb_hcd *hcd = dev_get_drvdata(&dwc->xhci->dev);

>>>> +     struct xhci_hcd *xhci = hcd_to_xhci(hcd);

>>>> +

>>>> +     return xhci_resume(xhci, 0);

>>>> +}

>>>

>>> This is wrong. XHCI is a child of dwc3, when dwc3 suspends,

>>> xhci_supend() has already been called. Why isn't it called for you?

>>

>> xhci-plat.c did not set the runtime PM callbacks, how can we issued

>> xhci_supend() by runtime PM from dwc3?

>

> wouldn't it be nicer to just initialize PM runtime callbacks from

> xhci-plat? It just needs to be added and verified, right?


Yes, you are right. Alan and Peter also suggested me to implement the
runtime PM callbacks for xhci-plat. I am also testing this and I will
send out the patch if it works well. So please ignore this patch.
Thanks for your comments.

-- 
Baolin.wang
Best Regards
diff mbox

Patch

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index a64ce1c..725d2bd 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -45,6 +45,13 @@  config USB_DWC3_DUAL_ROLE
 	  This is the default mode of working of DWC3 controller where
 	  both host and gadget features are enabled.
 
+config USB_DWC3_HOST_SUSPEND
+	bool "Choose if the host (xhci) can be suspend/resume"
+	depends on USB_DWC3_HOST=y || USB_DWC3_DUAL_ROLE=y
+	help
+	  We can suspend the host when the slave is detached for power saving,
+	  and resume the host when one slave is attached.
+
 endchoice
 
 comment "Platform Glue Driver Support"
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 1485480..5140b4d 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1103,15 +1103,27 @@  static int dwc3_remove(struct platform_device *pdev)
 static int dwc3_suspend_common(struct dwc3 *dwc)
 {
 	unsigned long	flags;
+	int		ret;
 
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_gadget_suspend(dwc);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		break;
 	case USB_DR_MODE_OTG:
+		ret = dwc3_host_suspend(dwc);
+		if (ret)
+			return ret;
+
 		spin_lock_irqsave(&dwc->lock, flags);
 		dwc3_gadget_suspend(dwc);
 		spin_unlock_irqrestore(&dwc->lock, flags);
 		break;
 	case USB_DR_MODE_HOST:
+		ret = dwc3_host_suspend(dwc);
+		if (ret)
+			return ret;
 	default:
 		/* do nothing */
 		break;
@@ -1133,12 +1145,23 @@  static int dwc3_resume_common(struct dwc3 *dwc)
 
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_gadget_resume(dwc);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		break;
 	case USB_DR_MODE_OTG:
+		ret = dwc3_host_resume(dwc);
+		if (ret)
+			return ret;
+
 		spin_lock_irqsave(&dwc->lock, flags);
 		dwc3_gadget_resume(dwc);
 		spin_unlock_irqrestore(&dwc->lock, flags);
-		/* FALLTHROUGH */
+		break;
 	case USB_DR_MODE_HOST:
+		ret = dwc3_host_resume(dwc);
+		if (ret)
+			return ret;
 	default:
 		/* do nothing */
 		break;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 45d6de5..0ba203e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1177,4 +1177,19 @@  static inline void dwc3_ulpi_exit(struct dwc3 *dwc)
 { }
 #endif
 
+#if IS_ENABLED(USB_DWC3_HOST_SUSPEND)
+int dwc3_host_suspend(struct dwc3 *dwc);
+int dwc3_host_resume(struct dwc3 *dwc);
+#else
+static inline int dwc3_host_suspend(struct dwc3 *dwc)
+{
+	return 0;
+}
+
+static inline int dwc3_host_resume(struct dwc3 *dwc)
+{
+	return 0;
+}
+#endif
+
 #endif /* __DRIVERS_USB_DWC3_CORE_H */
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 2e960ed..2ec3eff 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -17,8 +17,11 @@ 
 
 #include <linux/platform_device.h>
 #include <linux/usb/xhci_pdriver.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
 
 #include "core.h"
+#include "../host/xhci.h"
 
 int dwc3_host_init(struct dwc3 *dwc)
 {
@@ -91,6 +94,8 @@  int dwc3_host_init(struct dwc3 *dwc)
 	memset(&pdata, 0, sizeof(pdata));
 
 	pdata.usb3_lpm_capable = dwc->usb3_lpm_capable;
+	/* dwc3 controller need an extraordinary delay when suspending xhci. */
+	pdata.usb3_slow_suspend = 1;
 
 	ret = platform_device_add_data(xhci, &pdata, sizeof(pdata));
 	if (ret) {
@@ -128,3 +133,30 @@  void dwc3_host_exit(struct dwc3 *dwc)
 			  dev_name(&dwc->xhci->dev));
 	platform_device_unregister(dwc->xhci);
 }
+
+int dwc3_host_suspend(struct dwc3 *dwc)
+{
+	struct usb_hcd *hcd = dev_get_drvdata(&dwc->xhci->dev);
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	int ret, cnt = 20;
+
+try_again:
+	 /* We should wait for xhci bus has been into suspend mode firstly. */
+	ret = xhci_suspend(xhci, device_may_wakeup(&dwc->xhci->dev));
+	if (ret && --cnt > 0) {
+		dev_warn(dwc->dev, "xhci suspend failed %d, try again...\n",
+			 ret);
+		msleep(200);
+		goto try_again;
+	}
+
+	return ret;
+}
+
+int dwc3_host_resume(struct dwc3 *dwc)
+{
+	struct usb_hcd *hcd = dev_get_drvdata(&dwc->xhci->dev);
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+	return xhci_resume(xhci, 0);
+}