| Message ID | 1628058245-30692-1-git-send-email-wcheng@codeaurora.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] usb: dwc3: gadget: Avoid runtime resume if disabling pullup | expand |
Wesley Cheng <wcheng@codeaurora.org> writes: > If the device is already in the runtime suspended state, any call to > the pullup routine will issue a runtime resume on the DWC3 core > device. If the USB gadget is disabling the pullup, then avoid having > to issue a runtime resume, as DWC3 gadget has already been > halted/stopped. > > This fixes an issue where the following condition occurs: > > usb_gadget_remove_driver() > -->usb_gadget_disconnect() > -->dwc3_gadget_pullup(0) > -->pm_runtime_get_sync() -> ret = 0 > -->pm_runtime_put() [async] > -->usb_gadget_udc_stop() > -->dwc3_gadget_stop() > -->dwc->gadget_driver = NULL > ... > > dwc3_suspend_common() > -->dwc3_gadget_suspend() > -->DWC3 halt/stop routine skipped, driver_data == NULL > > This leads to a situation where the DWC3 gadget is not properly > stopped, as the runtime resume would have re-enabled EP0 and event > interrupts, and since we avoided the DWC3 gadget suspend, these > resources were never disabled. > > Fixes: 77adb8bdf422 ("usb: dwc3: gadget: Allow runtime suspend if UDC unbinded") > Signed-off-by: Wesley Cheng <wcheng@codeaurora.org> Acked-by: Felipe Balbi <balbi@kernel.org>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index a29a4ca..5d08454 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2435,6 +2435,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) } /* + * Avoid issuing a runtime resume if the device is already in the + * suspended state during gadget disconnect. DWC3 gadget was already + * halted/stopped during runtime suspend. + */ + if (!is_on) { + pm_runtime_barrier(dwc->dev); + if (pm_runtime_suspended(dwc->dev)) + return 0; + } + + /* * Check the return value for successful resume, or error. For a * successful resume, the DWC3 runtime PM resume routine will handle * the run stop sequence, so avoid duplicate operations here.
If the device is already in the runtime suspended state, any call to the pullup routine will issue a runtime resume on the DWC3 core device. If the USB gadget is disabling the pullup, then avoid having to issue a runtime resume, as DWC3 gadget has already been halted/stopped. This fixes an issue where the following condition occurs: usb_gadget_remove_driver() -->usb_gadget_disconnect() -->dwc3_gadget_pullup(0) -->pm_runtime_get_sync() -> ret = 0 -->pm_runtime_put() [async] -->usb_gadget_udc_stop() -->dwc3_gadget_stop() -->dwc->gadget_driver = NULL ... dwc3_suspend_common() -->dwc3_gadget_suspend() -->DWC3 halt/stop routine skipped, driver_data == NULL This leads to a situation where the DWC3 gadget is not properly stopped, as the runtime resume would have re-enabled EP0 and event interrupts, and since we avoided the DWC3 gadget suspend, these resources were never disabled. Fixes: 77adb8bdf422 ("usb: dwc3: gadget: Allow runtime suspend if UDC unbinded") Signed-off-by: Wesley Cheng <wcheng@codeaurora.org> --- Changes in v2: - Added fixes tag with the problem commit. drivers/usb/dwc3/gadget.c | 11 +++++++++++ 1 file changed, 11 insertions(+)