Commit df62df56 authored by Felipe Balbi's avatar Felipe Balbi
Browse files

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: default avatarFelipe Balbi <balbi@ti.com>
parent 05870c5b

drivers/usb/dwc3/core.h

+2 −0
Original line number Diff line number Diff line
@@ -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;

drivers/usb/dwc3/ep0.c

+3 −0
Original line number Diff line number Diff line
@@ -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

drivers/usb/dwc3/gadget.c

+32 −0
Original line number Diff line number Diff line
@@ -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);