DWC3 revisions <1.88a have an issue which would
case a missing Disconnect event if cable is
disconnected while there's a Setup packet
pending the FIFO.
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/dwc3/core.h | 2 ++
drivers/usb/dwc3/ep0.c | 3 +++
drivers/usb/dwc3/gadget.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index b901a4d..836cf99 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -578,6 +578,7 @@ struct dwc3_hwparams {
* @ep0_bounced: true when we used bounce buffer
* @ep0_expect_in: true when we expect a DATA IN transfer
* @start_config_issued: true when StartConfig command has been issued
+ * @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
* @ep0_next_event: hold the next expected event
* @ep0state: state of endpoint zero
* @link_state: link state
@@ -633,6 +634,7 @@ struct dwc3 {
unsigned ep0_bounced:1;
unsigned ep0_expect_in:1;
unsigned start_config_issued:1;
+ unsigned setup_packet_pending:1;
unsigned delayed_status:1;
enum dwc3_ep0_next ep0_next_event;
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 314acb2..ed44525 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -625,6 +625,7 @@ static void dwc3_ep0_xfer_complete(struct dwc3 *dwc,
struct dwc3_ep *dep = dwc->eps[event->endpoint_number];
dep->flags &= ~DWC3_EP_BUSY;
+ dwc->setup_packet_pending = false;
switch (dwc->ep0state) {
case EP0_SETUP_PHASE:
@@ -726,6 +727,8 @@ static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum)
static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
const struct dwc3_event_depevt *event)
{
+ dwc->setup_packet_pending = true;
+
/*
* This part is very tricky: If we has just handled
* XferNotReady(Setup) and we're now expecting a
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index bd94334..211100f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1640,6 +1640,7 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
dwc->start_config_issued = false;
dwc->gadget.speed = USB_SPEED_UNKNOWN;
+ dwc->setup_packet_pending = false;
}
static void dwc3_gadget_usb3_phy_power(struct dwc3 *dwc, int on)
@@ -1676,6 +1677,37 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
dev_vdbg(dwc->dev, "%s\n", __func__);
+ /*
+ * WORKAROUND: DWC3 revisions <1.88a have an issue which
+ * would cause a missing Disconnect Event if there's a
+ * pending Setup Packet in the FIFO.
+ *
+ * There's no suggested workaround on the official Bug
+ * report, which states that "unless the driver/application
+ * is doing any special handling of a disconnect event,
+ * there is no functional issue".
+ *
+ * Unfortunately, it turns out that we _do_ some special
+ * handling of a disconnect event, namely complete all
+ * pending transfers, notify gadget driver of the
+ * disconnection, and so on.
+ *
+ * Our suggested workaround is to follow the Disconnect
+ * Event steps here, instead, based on a setup_packet_pending
+ * flag. Such flag gets set whenever we have a XferNotReady
+ * event on EP0 and gets cleared on XferComplete for the
+ * same endpoint.
+ *
+ * Refers to:
+ *
+ * STAR#9000466709: RTL: Device : Disconnect event not
+ * generated if setup packet pending in FIFO
+ */
+ if (dwc->revision < DWC3_REVISION_188A) {
+ if (dwc->setup_packet_pending)
+ dwc3_gadget_disconnect_interrupt(dwc);
+ }
+
/* Enable PHYs */
dwc3_gadget_usb2_phy_power(dwc, true);
dwc3_gadget_usb3_phy_power(dwc, true);
--
1.7.8.rc3
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
