On 7/12/2017 12:19 PM, Baolin Wang wrote:
Hi,

On 3 July 2017 at 19:25, Manu Gautam <mgau...@codeaurora.org> 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.
But for some mobile devices, they also need suspend/resume in host
mode which will power off dwc3 controller in glue layer. If we remove
dwc3_core_init() for host mode, I am afraid it can not work well in
host mode after resuming dwc3.
Can you point me to a glue driver doing that?
If dwc3 is powered off on suspend then Xhci level initialization also needed after performing dwc3_core_init on resume which is currently not present. So this seems
to me broken anyway.
Also, powering off dwc3 on suspend by default from dwc3 core may not be correct and better left to glue drivers as some platforms might not want to reinitialize host
after suspend/resume. This can be achieved by exposing dwc3_core_init and
dwc3_core_init_mode to glue drivers.
Signed-off-by: Manu Gautam <mgau...@codeaurora.org>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index c22c37d..fc556a4 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -924,6 +924,7 @@ 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);
                 ret = dwc3_gadget_init(dwc);
                 if (ret) {
@@ -933,6 +934,7 @@ 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);
                 ret = dwc3_host_init(dwc);
                 if (ret) {
@@ -1280,21 +1282,19 @@ 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;
  }

@@ -1303,18 +1303,17 @@ 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;
@@ -1325,7 +1324,7 @@ 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)
@@ -1368,12 +1367,11 @@ 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;
@@ -1389,13 +1387,12 @@ 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;
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na 
Linux Foundation Collaborative Project

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