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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>,
        "Geert Uytterhoeven" <geert+renesas@glider.be>,
        Colin Ian King <colin.i.king@gmail.com>,
        Jiantao Zhang <water.zhangjiantao@huawei.com>,
        "Rafael J . Wysocki" <rafael@kernel.org>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_ppratap@quicinc.com>, <quic_wcheng@quicinc.com>,
        <quic_jackp@quicinc.com>, <quic_ugoswami@quicinc.com>,
        Krishna Kurapati <quic_kriskura@quicinc.com>
Subject: [PATCH v2 1/2] usb: dwc3: gadget: Bail out in pullup if soft reset timeout happens
Date:   Tue, 28 Mar 2023 21:37:55 +0530
Message-ID: <20230328160756.30520-2-quic_kriskura@quicinc.com>
In-Reply-To: <20230328160756.30520-1-quic_kriskura@quicinc.com>
References: <20230328160756.30520-1-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>
---
 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 3c63fa97a680..f0472801d9a5 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2620,13 +2620,16 @@ 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, false);
 	}
 
+done:
 	pm_runtime_put(dwc->dev);
 
 	return ret;
-- 
2.40.0