Re: [RESEND PATCH 1/3] usb: dwc3: Don't reinitialize core during host bus-suspend/resume

[Manu Gautam]

Hi Felipe,

Let me know if patches in this series look fine to you.


On 9/27/2017 4:49 PM, Manu Gautam wrote:
> Driver powers-off PHYs and reinitializes DWC3 core and gadget on
> resume. While this works fine for gadget mode but in host
> mode there is not re-initialization of host stack. Also, resetting
> bus as part of bus_suspend/resume is not correct which could affect
> (or disconnect) connected devices.
> Fix this by not reinitializing core on suspend/resume in host mode
> for HOST only and OTG/drd configurations.
>
> Signed-off-by: Manu Gautam <mgautam@xxxxxxxxxxxxxx>
> ---
>  drivers/usb/dwc3/core.c | 43 ++++++++++++++++++++-----------------------
>  1 file changed, 20 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 03474d3..f75613f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -927,6 +927,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
>  
>  	switch (dwc->dr_mode) {
>  	case USB_DR_MODE_PERIPHERAL:
> +		dwc->current_dr_role = DWC3_GCTL_PRTCAP_DEVICE;
>  		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
>  
>  		if (dwc->usb2_phy)
> @@ -942,6 +943,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
>  		}
>  		break;
>  	case USB_DR_MODE_HOST:
> +		dwc->current_dr_role = DWC3_GCTL_PRTCAP_HOST;
>  		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
>  
>  		if (dwc->usb2_phy)
> @@ -1293,21 +1295,19 @@ static int dwc3_suspend_common(struct dwc3 *dwc)
>  {
>  	unsigned long	flags;
>  
> -	switch (dwc->dr_mode) {
> -	case USB_DR_MODE_PERIPHERAL:
> -	case USB_DR_MODE_OTG:
> +	switch (dwc->current_dr_role) {
> +	case DWC3_GCTL_PRTCAP_DEVICE:
>  		spin_lock_irqsave(&dwc->lock, flags);
>  		dwc3_gadget_suspend(dwc);
>  		spin_unlock_irqrestore(&dwc->lock, flags);
> +		dwc3_core_exit(dwc);
>  		break;
> -	case USB_DR_MODE_HOST:
> +	case DWC3_GCTL_PRTCAP_HOST:
>  	default:
>  		/* do nothing */
>  		break;
>  	}
>  
> -	dwc3_core_exit(dwc);
> -
>  	return 0;
>  }
>  
> @@ -1316,18 +1316,17 @@ static int dwc3_resume_common(struct dwc3 *dwc)
>  	unsigned long	flags;
>  	int		ret;
>  
> -	ret = dwc3_core_init(dwc);
> -	if (ret)
> -		return ret;
> +	switch (dwc->current_dr_role) {
> +	case DWC3_GCTL_PRTCAP_DEVICE:
> +		ret = dwc3_core_init(dwc);
> +		if (ret)
> +			return ret;
>  
> -	switch (dwc->dr_mode) {
> -	case USB_DR_MODE_PERIPHERAL:
> -	case USB_DR_MODE_OTG:
>  		spin_lock_irqsave(&dwc->lock, flags);
>  		dwc3_gadget_resume(dwc);
>  		spin_unlock_irqrestore(&dwc->lock, flags);
> -		/* FALLTHROUGH */
> -	case USB_DR_MODE_HOST:
> +		break;
> +	case DWC3_GCTL_PRTCAP_HOST:
>  	default:
>  		/* do nothing */
>  		break;
> @@ -1338,7 +1337,7 @@ static int dwc3_resume_common(struct dwc3 *dwc)
>  
>  static int dwc3_runtime_checks(struct dwc3 *dwc)
>  {
> -	switch (dwc->dr_mode) {
> +	switch (dwc->current_dr_role) {
>  	case USB_DR_MODE_PERIPHERAL:
>  	case USB_DR_MODE_OTG:
>  		if (dwc->connected)
> @@ -1381,12 +1380,11 @@ static int dwc3_runtime_resume(struct device *dev)
>  	if (ret)
>  		return ret;
>  
> -	switch (dwc->dr_mode) {
> -	case USB_DR_MODE_PERIPHERAL:
> -	case USB_DR_MODE_OTG:
> +	switch (dwc->current_dr_role) {
> +	case DWC3_GCTL_PRTCAP_DEVICE:
>  		dwc3_gadget_process_pending_events(dwc);
>  		break;
> -	case USB_DR_MODE_HOST:
> +	case DWC3_GCTL_PRTCAP_HOST:
>  	default:
>  		/* do nothing */
>  		break;
> @@ -1402,13 +1400,12 @@ static int dwc3_runtime_idle(struct device *dev)
>  {
>  	struct dwc3     *dwc = dev_get_drvdata(dev);
>  
> -	switch (dwc->dr_mode) {
> -	case USB_DR_MODE_PERIPHERAL:
> -	case USB_DR_MODE_OTG:
> +	switch (dwc->current_dr_role) {
> +	case DWC3_GCTL_PRTCAP_DEVICE:
>  		if (dwc3_runtime_checks(dwc))
>  			return -EBUSY;
>  		break;
> -	case USB_DR_MODE_HOST:
> +	case DWC3_GCTL_PRTCAP_HOST:
>  	default:
>  		/* do nothing */
>  		break;

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