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Commit f8eff12c authored by Bar Weiner's avatar Bar Weiner Committed by Matt Wagantall
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usb: dwc3: gadget: allow running wakeup in delayed context 



Adding the option of running the gadget wakeup function
from the context in which it is called, or delaying it - in case
it is called from an atomic context. This is required in order
to support a case where the gadget is in lpm and the wakeup
would result in a queue to the low-powered hardware.

Change-Id: I09fc60e75c79202c97251146aab1539de3307424
Signed-off-by: default avatarBar Weiner <bweiner@codeaurora.org>
Signed-off-by: default avatarDanny Segal <dsegal@codeaurora.org>
[jackp@codeaurora.org: Merged struct dwc3_usb_gadget into struct dwc3]
Signed-off-by: default avatarJack Pham <jackp@codeaurora.org>
parent e8db3c5c

drivers/usb/dwc3/core.h

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/dma-mapping.h>

#include <linux/mm.h>

#include <linux/debugfs.h>

#include <linux/workqueue.h>



#include <linux/usb/ch9.h>

#include <linux/usb/gadget.h>
@@ -879,6 +880,7 @@ struct dwc3 { 
	u8			test_mode_nr;



	void (*notify_event)	(struct dwc3 *, unsigned);

	struct work_struct	wakeup_work;



	unsigned		delayed_status:1;

	unsigned		ep0_bounced:1;

drivers/usb/dwc3/gadget.c

+69 −17
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include "io.h"



static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc);

static int dwc3_gadget_wakeup_int(struct dwc3 *dwc);



/**

 * dwc3_gadget_set_test_mode - Enables USB2 Test Modes
@@ -1168,6 +1169,39 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) 
	return 0;

}



static int dwc3_gadget_wakeup(struct usb_gadget *g)

{

	struct dwc3		*dwc = gadget_to_dwc(g);

	unsigned long		flags;

	int			ret = 0;



	spin_lock_irqsave(&dwc->lock, flags);



	if (atomic_read(&dwc->in_lpm)) {

		schedule_work(&dwc->wakeup_work);

		pr_debug("Core is in low-power mode. Scheduling wakeup work.\n");

		ret = -EBUSY;

	} else {

		pr_debug("Core is active. Initiating remote wakeup.\n");

		ret = dwc3_gadget_wakeup_int(dwc);

		if (ret)

			pr_err("Remote wakeup failed. ret = %d\n", ret);

		else

			pr_debug("Remote wake up succeeded.\n");

	}



	spin_unlock_irqrestore(&dwc->lock, flags);



	return ret;

}



static inline enum dwc3_link_state dwc3_get_link_state(struct dwc3 *dwc)

{

	u32 reg;

	reg = dwc3_readl(dwc->regs, DWC3_DSTS);

	return DWC3_DSTS_USBLNKST(reg);

}



static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,

	gfp_t gfp_flags)

{
@@ -1385,31 +1419,48 @@ static int dwc3_gadget_get_frame(struct usb_gadget *g) 
	return DWC3_DSTS_SOFFN(reg);

}



static int dwc3_gadget_wakeup(struct usb_gadget *g)

static void dwc3_gadget_wakeup_work(struct work_struct *w)

{

	struct dwc3		*dwc = gadget_to_dwc(g);



	unsigned long		timeout;

	struct dwc3		*dwc;

	unsigned long		flags;

	int			ret;



	dwc = container_of(w, struct dwc3, wakeup_work);



	spin_lock_irqsave(&dwc->lock, flags);



	if (atomic_read(&dwc->in_lpm)) {

		spin_unlock_irqrestore(&dwc->lock, flags);

		pm_runtime_get_sync(dwc->dev);

		spin_lock_irqsave(&dwc->lock, flags);

	}



	ret = dwc3_gadget_wakeup_int(dwc);



	if (ret)

		pr_err("Remote wakeup failed. ret = %d.\n", ret);

	else

		pr_debug("Remote wakeup succeeded.\n");



	spin_unlock_irqrestore(&dwc->lock, flags);

}



static int dwc3_gadget_wakeup_int(struct dwc3 *dwc)

{

	u32			timeout = 0;

	bool			link_recover_only = false;



	u32			reg;



	int			ret = 0;



	u8			link_state;



	spin_lock_irqsave(&dwc->lock, flags);



	/*

	 * According to the Databook Remote wakeup request should

	 * be issued only when the device is in early suspend state.

	 *

	 * We can check that via USB Link State bits in DSTS register.

	 */

	reg = dwc3_readl(dwc->regs, DWC3_DSTS);



	link_state = DWC3_DSTS_USBLNKST(reg);

	link_state = dwc3_get_link_state(dwc);



	switch (link_state) {

	case DWC3_LINK_STATE_RX_DET:	/* in HS, means Early Suspend */
@@ -1443,21 +1494,21 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g) 
	}



	/* poll until Link State changes to ON */

	timeout = jiffies + msecs_to_jiffies(100);



	spin_unlock_irqrestore(&dwc->lock, flags);

	while (!time_after(jiffies, timeout)) {

	do {

		reg = dwc3_readl(dwc->regs, DWC3_DSTS);



		/* in HS, means ON */

		if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0)

			break;

	}

	spin_lock_irqsave(&dwc->lock, flags);

		udelay(10);

		timeout++;

	} while (timeout < 10000);



	if (DWC3_DSTS_USBLNKST(reg) != DWC3_LINK_STATE_U0) {

		dev_err(dwc->dev, "failed to send remote wakeup\n");

		ret = -EINVAL;

		goto out;

	}



	/*
@@ -1470,7 +1521,6 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g) 
	if (!link_recover_only)

		dwc3_gadget_wakeup_interrupt(dwc);

out:

	spin_unlock_irqrestore(&dwc->lock, flags);



	return ret;

}
@@ -3020,6 +3070,8 @@ int dwc3_gadget_init(struct dwc3 *dwc) 
{

	int					ret;



	INIT_WORK(&dwc->wakeup_work, dwc3_gadget_wakeup_work);



	dwc->ctrl_req = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ctrl_req),

			&dwc->ctrl_req_addr, GFP_KERNEL);

	if (!dwc->ctrl_req) {