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From:   Krishna Kurapati <quic_kriskura@quicinc.com>
To:     Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        "Jiantao Zhang" <water.zhangjiantao@huawei.com>,
        Badhri Jagan Sridharan <badhri@google.com>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_ppratap@quicinc.com>, <quic_wcheng@quicinc.com>,
        <quic_jackp@quicinc.com>,
        Krishna Kurapati <quic_kriskura@quicinc.com>
Subject: [PATCH v3 1/2] usb: dwc3: gadget: Bail out in pullup if soft reset timeout happens
Date:   Wed, 10 May 2023 13:22:51 +0530
Message-ID: <20230510075252.31023-2-quic_kriskura@quicinc.com>
In-Reply-To: <20230510075252.31023-1-quic_kriskura@quicinc.com>
References: <20230510075252.31023-1-quic_kriskura@quicinc.com>
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If the core soft reset timeout happens, avoid setting up event
buffers and starting gadget as the writes to these registers
may not reflect when in reset and setting the run stop bit
can lead the controller to access wrong event buffer address
resulting in a crash.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
---
changes in v3: Rebase on top of usb-next

 drivers/usb/dwc3/gadget.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c0ca4d12f95d..9ab5161881bd 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2746,13 +2746,16 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 		 * device-initiated disconnect requires a core soft reset
 		 * (DCTL.CSftRst) before enabling the run/stop bit.
 		 */
-		dwc3_core_soft_reset(dwc);
+		ret = dwc3_core_soft_reset(dwc);
+		if (ret)
+			goto done;
 
 		dwc3_event_buffers_setup(dwc);
 		__dwc3_gadget_start(dwc);
 		ret = dwc3_gadget_run_stop(dwc, true);
 	}
 
+done:
 	pm_runtime_put(dwc->dev);
 
 	return ret;
-- 
2.40.0