| Message ID | 1627691374-15711-1-git-send-email-wcheng@codeaurora.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: dwc3: gadget: Avoid runtime resume if disabling pullup | expand |
Hi Wesley, On Fri, Jul 30, 2021 at 05:29:34PM -0700, Wesley Cheng wrote: > 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. > > Signed-off-by: Wesley Cheng <wcheng@codeaurora.org> > --- > drivers/usb/dwc3/gadget.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > 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. Should this also go to stable with Fixes: 77adb8bdf422 ("usb: dwc3: gadget: Allow runtime suspend if UDC unbinded") ? Jack
Jack Pham <jackp@codeaurora.org> writes: > Hi Wesley, > > On Fri, Jul 30, 2021 at 05:29:34PM -0700, Wesley Cheng wrote: >> 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. >> >> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org> >> --- >> drivers/usb/dwc3/gadget.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> 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. > > Should this also go to stable with Fixes: 77adb8bdf422 ("usb: dwc3: > gadget: Allow runtime suspend if UDC unbinded") ? sounds like a good idea. -- balbi
On 8/3/2021 12:58 AM, Felipe Balbi wrote: > > Jack Pham <jackp@codeaurora.org> writes: > >> Hi Wesley, >> >> On Fri, Jul 30, 2021 at 05:29:34PM -0700, Wesley Cheng wrote: >>> 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. >>> >>> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org> >>> --- >>> drivers/usb/dwc3/gadget.c | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> 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. Hi Jack/Felipe, >> >> Should this also go to stable with Fixes: 77adb8bdf422 ("usb: dwc3: >> gadget: Allow runtime suspend if UDC unbinded") ? > > sounds like a good idea. > Sure, will update the commit text with the fixes tag. Thanks! Regards, Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
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. Signed-off-by: Wesley Cheng <wcheng@codeaurora.org> --- drivers/usb/dwc3/gadget.c | 11 +++++++++++ 1 file changed, 11 insertions(+)