According to Synopsys Programming Guide chapter 2.2 Register Resets,
it cannot reset the DCTL register by set DCTL.CSFTRST for Core Soft Reset,
if DWC3 controller as a slave device and stay connected with a usb host,
then, reboot 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 clear DCTL.RUN_STOP bit for disable connect
when do core soft reset.
Fixes: f59dcab176293b6 ("usb: dwc3: core: improve reset sequence")
Signed-off-by: Dejin Zheng <zhengdejin5@xxxxxxxxx>
---
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
