From c96683798e272366866a5c0ce3073c0b5a256db7 Mon Sep 17 00:00:00 2001

From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Date: Thu, 21 Apr 2022 19:22:50 -0700

Subject: [PATCH] usb: dwc3: ep0: Don't prepare beyond Setup stage

Git-commit: c96683798e272366866a5c0ce3073c0b5a256db7

References: git-fixes

Patch-mainline: v5.19-rc1

Since we can't guarantee that the host won't send new Setup packet

before going through the device-initiated disconnect, don't prepare

beyond the Setup stage and keep the device in EP0_SETUP_PHASE. This

ensures that the device-initated disconnect sequence can go through

gracefully. Note that the controller won't service the End Transfer

command if it can't DMA out the Setup packet.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Link: https://lore.kernel.org/r/6bacec56ecabb2c6e49a09cedfcac281fdc97de0.1650593829.git.Thinh.Nguyen@synopsys.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Oliver Neukum <oneukum@suse.com>

---

 drivers/usb/dwc3/ep0.c    |  2 +-

 drivers/usb/dwc3/gadget.c | 29 +++++++++++++++++------------

 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c

index aa8476da222d..6615f641b34f 100644

--- a/drivers/usb/dwc3/ep0.c

+++ b/drivers/usb/dwc3/ep0.c

@@ -813,7 +813,7 @@ static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,

 	int ret = -EINVAL;

 	u32 len;

-	if (!dwc->gadget_driver)

+	if (!dwc->gadget_driver || !dwc->connected)

 		goto out;

 	trace_dwc3_ctrl_req(ctrl);

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c

index 3c0a6c83ea43..5e3311e3cc16 100644

--- a/drivers/usb/dwc3/gadget.c

+++ b/drivers/usb/dwc3/gadget.c

@@ -2514,6 +2514,23 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc)

 	spin_lock_irqsave(&dwc->lock, flags);

 	dwc->connected = false;

+	/*

+	 * Per databook, when we want to stop the gadget, if a control transfer

+	 * is still in process, complete it and get the core into setup phase.

+	 */

+	if (dwc->ep0state != EP0_SETUP_PHASE) {

+		int ret;

+

+		reinit_completion(&dwc->ep0_in_setup);

+

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

+		ret = wait_for_completion_timeout(&dwc->ep0_in_setup,

+				msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT));

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

+		if (ret == 0)

+			dev_warn(dwc->dev, "timed out waiting for SETUP phase\n");

+	}

+

 	/*

 	 * In the Synopsys DesignWare Cores USB3 Databook Rev. 3.30a

 	 * Section 4.1.8 Table 4-7, it states that for a device-initiated

@@ -2546,18 +2563,6 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)

 		return 0;

 	dwc->softconnect = is_on;

-	/*

-	 * Per databook, when we want to stop the gadget, if a control transfer

-	 * is still in process, complete it and get the core into setup phase.

-	 */

-	if (!is_on && dwc->ep0state != EP0_SETUP_PHASE) {

-		reinit_completion(&dwc->ep0_in_setup);

-

-		ret = wait_for_completion_timeout(&dwc->ep0_in_setup,

-				msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT));

-		if (ret == 0)

-			dev_warn(dwc->dev, "timed out waiting for SETUP phase\n");

-	}

 	/*

 	 * Avoid issuing a runtime resume if the device is already in the

-- 

2.40.1