Re: [PATCH v1] usb: dwc3: core: fix a issue about clear connect state

From: Felipe Balbi
Date: Tue Oct 27 2020 - 05:12:21 EST


Hi,

Dejin Zheng <zhengdejin5@xxxxxxxxx> writes:
> 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;

as I mentioned in the other thread, I would rather figure out why we're
getting to probe() with RUN_STOP already set.

--
balbi