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Commit c40cf770 authored by Douglas Anderson's avatar Douglas Anderson Committed by Felipe Balbi
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usb: dwc2: optionally assert phy reset when waking up 



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), 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: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarYunzhi Li <lyz@rock-chips.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent cc389eaa

drivers/usb/dwc2/core.h

+8 −0
Original line number Diff line number Diff line
@@ -859,6 +859,8 @@ struct dwc2_hregs_backup { 
 * @gadget_enabled:	Peripheral mode sub-driver initialization indicator.

 * @ll_hw_enabled:	Status of low-level hardware resources.

 * @hibernated:		True if core is hibernated

 * @reset_phy_on_wake:	Quirk saying that we should assert PHY reset on a

 *			remote wakeup.

 * @frame_number:       Frame number read from the core. For both device

 *			and host modes. The value ranges are from 0

 *			to HFNUM_MAX_FRNUM.
@@ -972,6 +974,7 @@ struct dwc2_hregs_backup { 
 * @status_buf_dma:     DMA address for status_buf

 * @start_work:         Delayed work for handling host A-cable connection

 * @reset_work:         Delayed work for handling a port reset

 * @phy_reset_work:     Work structure for doing a PHY reset

 * @otg_port:           OTG port number

 * @frame_list:         Frame list

 * @frame_list_dma:     Frame list DMA address
@@ -1045,6 +1048,7 @@ struct dwc2_hsotg { 
	unsigned int gadget_enabled:1;

	unsigned int ll_hw_enabled:1;

	unsigned int hibernated:1;

	unsigned int reset_phy_on_wake:1;

	u16 frame_number;



	struct phy *phy;
@@ -1147,6 +1151,7 @@ struct dwc2_hsotg { 


	struct delayed_work start_work;

	struct delayed_work reset_work;

	struct work_struct phy_reset_work;

	u8 otg_port;

	u32 *frame_list;

	dma_addr_t frame_list_dma;
@@ -1431,6 +1436,8 @@ int dwc2_restore_host_registers(struct dwc2_hsotg *hsotg); 
int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg);

int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg,

			       int rem_wakeup, int reset);

static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg)

{ schedule_work(&hsotg->phy_reset_work); }

#else

static inline int dwc2_hcd_get_frame_number(struct dwc2_hsotg *hsotg)

{ return 0; }
@@ -1454,6 +1461,7 @@ static inline int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg) 
static inline int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg,

					     int rem_wakeup, int reset)

{ return 0; }

static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg) {}



#endif

drivers/usb/dwc2/core_intr.c

+12 −0
Original line number Diff line number Diff line
@@ -435,6 +435,18 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) 
			/* Restart the Phy Clock */

			pcgcctl &= ~PCGCTL_STOPPCLK;

			dwc2_writel(hsotg, pcgcctl, 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.  We can't call phy_reset()

			 * at interrupt time but there's no hurry, so we'll

			 * schedule it for later.

			 */

			if (hsotg->reset_phy_on_wake)

				dwc2_host_schedule_phy_reset(hsotg);



			mod_timer(&hsotg->wkp_timer,

				  jiffies + msecs_to_jiffies(71));

		} else {

drivers/usb/dwc2/hcd.c

+15 −3
Original line number Diff line number Diff line
@@ -4376,6 +4376,17 @@ static void dwc2_hcd_reset_func(struct work_struct *work) 
	spin_unlock_irqrestore(&hsotg->lock, flags);

}



static void dwc2_hcd_phy_reset_func(struct work_struct *work)

{

	struct dwc2_hsotg *hsotg = container_of(work, struct dwc2_hsotg,

						phy_reset_work);

	int ret;



	ret = phy_reset(hsotg->phy);

	if (ret)

		dev_warn(hsotg->dev, "PHY reset failed\n");

}



/*

 * =========================================================================

 *  Linux HC Driver Functions
@@ -5152,6 +5163,8 @@ static void dwc2_hcd_free(struct dwc2_hsotg *hsotg) 
		destroy_workqueue(hsotg->wq_otg);

	}



	cancel_work_sync(&hsotg->phy_reset_work);



	del_timer(&hsotg->wkp_timer);

}
@@ -5293,11 +5306,10 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg) 
		hsotg->hc_ptr_array[i] = channel;

	}



	/* Initialize hsotg start work */

	/* Initialize work */

	INIT_DELAYED_WORK(&hsotg->start_work, dwc2_hcd_start_func);



	/* Initialize port reset work */

	INIT_DELAYED_WORK(&hsotg->reset_work, dwc2_hcd_reset_func);

	INIT_WORK(&hsotg->phy_reset_work, dwc2_hcd_phy_reset_func);



	/*

	 * Allocate space for storing data on status transactions. Normally no

drivers/usb/dwc2/platform.c

+9 −0
Original line number Diff line number Diff line
@@ -481,6 +481,15 @@ static int dwc2_driver_probe(struct platform_device *dev) 
		hsotg->gadget_enabled = 1;

	}



	hsotg->reset_phy_on_wake =

		of_property_read_bool(dev->dev.of_node,

				      "snps,reset-phy-on-wake");

	if (hsotg->reset_phy_on_wake && !hsotg->phy) {

		dev_warn(hsotg->dev,

			 "Quirk reset-phy-on-wake only supports generic PHYs\n");

		hsotg->reset_phy_on_wake = false;

	}



	if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL) {

		retval = dwc2_hcd_init(hsotg);

		if (retval) {