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From:   Wesley Cheng <quic_wcheng@quicinc.com>
To:     <balbi@kernel.org>, <gregkh@linuxfoundation.org>,
        <Thinh.Nguyen@synopsys.com>
CC:     <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>,
        <quic_jackp@quicinc.com>, Wesley Cheng <quic_wcheng@quicinc.com>
Subject: [PATCH v4 6/9] usb: dwc3: Remove DWC3 locking during gadget suspend/resume
Date:   Wed, 17 Aug 2022 11:23:56 -0700
Message-ID: <20220817182359.13550-7-quic_wcheng@quicinc.com>
In-Reply-To: <20220817182359.13550-1-quic_wcheng@quicinc.com>
References: <20220817182359.13550-1-quic_wcheng@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Remove the need for making dwc3_gadget_suspend() and dwc3_gadget_resume()
to be called in a spinlock, as dwc3_gadget_run_stop() could potentially
take some time to complete.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/dwc3/core.c   | 4 ----
 drivers/usb/dwc3/gadget.c | 5 +++++
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index c5c238ab3083..23e123a1ab5f 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1976,9 +1976,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 	case DWC3_GCTL_PRTCAP_DEVICE:
 		if (pm_runtime_suspended(dwc->dev))
 			break;
-		spin_lock_irqsave(&dwc->lock, flags);
 		dwc3_gadget_suspend(dwc);
-		spin_unlock_irqrestore(&dwc->lock, flags);
 		synchronize_irq(dwc->irq_gadget);
 		dwc3_core_exit(dwc);
 		break;
@@ -2039,9 +2037,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
 			return ret;
 
 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
-		spin_lock_irqsave(&dwc->lock, flags);
 		dwc3_gadget_resume(dwc);
-		spin_unlock_irqrestore(&dwc->lock, flags);
 		break;
 	case DWC3_GCTL_PRTCAP_HOST:
 		if (!PMSG_IS_AUTO(msg) && !device_can_wakeup(dwc->dev)) {
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7b66a54250a0..57d83b3b4967 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -4520,12 +4520,17 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 
 int dwc3_gadget_suspend(struct dwc3 *dwc)
 {
+	unsigned long flags;
+
 	if (!dwc->gadget_driver)
 		return 0;
 
 	dwc3_gadget_run_stop(dwc, false, false);
+
+	spin_lock_irqsave(&dwc->lock, flags);
 	dwc3_disconnect_gadget(dwc);
 	__dwc3_gadget_stop(dwc);
+	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	return 0;
 }