Hi, [email protected] writes: > From: "Du, Changbin" <[email protected]> > > The dwc3 controller can't generate a disconnect event after it is > stopped. Thus gadget dissconnect callback is not invoked when do
not generating disconnect IRQ after you drop Run/Stop is expected. > soft dissconnect. Call dissconnect here to workaround this issue. I'm rather sure this is a bug elsewhere. How do you trigger this ? > Note, most time we still see disconnect be called that because > it is invoked by dwc3_gadget_reset_interrupt(). But if we > disconnect cable once pullup disabled quickly, issue can be > observed. I can't understand what you're trying to say with this. > Signed-off-by: Du, Changbin <[email protected]> > --- > drivers/usb/dwc3/gadget.c | 33 ++++++++++++++++++++++++--------- > 1 file changed, 24 insertions(+), 9 deletions(-) > > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c > index 8e4a1b1..cd73187 100644 > --- a/drivers/usb/dwc3/gadget.c > +++ b/drivers/usb/dwc3/gadget.c > @@ -1566,6 +1566,15 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int > is_on, int suspend) > return 0; > } > > +static void dwc3_disconnect_gadget(struct dwc3 *dwc) > +{ > + if (dwc->gadget_driver && dwc->gadget_driver->disconnect) { > + spin_unlock(&dwc->lock); > + dwc->gadget_driver->disconnect(&dwc->gadget); > + spin_lock(&dwc->lock); > + } > +} > + > static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) > { > struct dwc3 *dwc = gadget_to_dwc(g); > @@ -1575,6 +1584,21 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, > int is_on) > is_on = !!is_on; > > spin_lock_irqsave(&dwc->lock, flags); > + /** > + * WORKAROUND: The dwc3 controller can't generate a disconnect > + * event after it is stopped. Thus gadget dissconnect callback > + * is not invoked when do soft dissconnect. Call dissconnect > + * here to workaround this issue. > + * Note, most time we still see disconnect be called that because > + * it is invoked by dwc3_gadget_reset_interrupt(). But if we > + * disconnect cable once pullup disabled quickly, issue can be > + * observed. > + */ > + if (!is_on && (dwc->gadget.speed != USB_SPEED_UNKNOWN)) { > + dev_dbg(dwc->dev, "fake dissconnect event on pullup off\n"); > + dwc3_disconnect_gadget(dwc); > + dwc->gadget.speed = USB_SPEED_UNKNOWN; > + } this is *really* wrong. You shouldn't be calling pullup directly. This patch looks wrong and you didn't even explain how to trigger this problem; when does the problem happen ? Gadget load/unload does the right thing here, so that can't be the case. We also do the right thing on soft_connect sysfs file: static ssize_t usb_udc_softconn_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { struct usb_udc *udc = container_of(dev, struct usb_udc, dev); if (!udc->driver) { dev_err(dev, "soft-connect without a gadget driver\n"); return -EOPNOTSUPP; } if (sysfs_streq(buf, "connect")) { usb_gadget_udc_start(udc); usb_gadget_connect(udc->gadget); } else if (sysfs_streq(buf, "disconnect")) { usb_gadget_disconnect(udc->gadget); udc->driver->disconnect(udc->gadget); usb_gadget_udc_stop(udc); } else { dev_err(dev, "unsupported command '%s'\n", buf); return -EINVAL; } return n; } static DEVICE_ATTR(soft_connect, S_IWUSR, NULL, usb_udc_softconn_store); So really, what _is_ the problem ? -- balbi
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