From df62df56e13d73cb0dd4c54649d4fe13557128f8 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Fri, 14 Oct 2011 15:11:49 +0300 Subject: [PATCH] usb: dwc3: workaround: missing disconnect event 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 --- drivers/usb/dwc3/core.h | 2 ++ drivers/usb/dwc3/ep0.c | 3 +++ drivers/usb/dwc3/gadget.c | 32 ++++++++++++++++++++++++++++++++ 3 files changed, 37 insertions(+) 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 6704a52..7c98b3f 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); -- 2.7.4