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@xxxxxxxxx>
---
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
