Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Dejin Zheng <zhengdejin5@gmail.com>
To:     balbi@kernel.org, gregkh@linuxfoundation.org,
        sergei.shtylyov@gmail.com, linux-usb@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, Dejin Zheng <zhengdejin5@gmail.com>
Subject: [PATCH v2] usb: dwc3: core: fix a issue about clear connect state
Date:   Mon, 19 Oct 2020 10:34:35 +0800
Message-Id: <20201019023435.5482-1-zhengdejin5@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

According to Synopsys Programming Guide chapter 2.2 Register Resets,
it cannot reset the DCTL register by setting DCTL.CSFTRST for core soft
reset, if DWC3 controller as a slave device and stay connected with a usb
host, then, while rebooting linux, it will fail to reinitialize dwc3 as a
slave device when the DWC3 controller did not power off. because the
connection status is incorrect, so we also need to clear DCTL.RUN_STOP
bit for disabling connect when doing core soft reset.

Fixes: f59dcab176293b6 ("usb: dwc3: core: improve reset sequence")
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v1 -> v2:
	* modify some commit messages by Sergei's suggest, Thanks
	  very much for Sergei's help!

 drivers/usb/dwc3/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 2eb34c8b4065..239636c454c2 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -256,6 +256,7 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
 
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 	reg |= DWC3_DCTL_CSFTRST;
+	reg &= ~DWC3_DCTL_RUN_STOP;
 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
 
 	/*
-- 
2.25.0