usb: dwc3: Do not service EP0 and conndone events if soft disconnected

There are some operations that need to be ignored if there is a soft
disconnect in progress.  This is to avoid having a pending EP0 transfer in
progress while attempting to stop active transfers and halting the
controller.

There were several instances seen where a soft disconnect was able to occur
during early link negotiation, i.e. bus reset/conndone, which leads to the
conndone handler re-configuring EPs while attempting to halt the
controller, as DEP flags are cleared as part of the soft disconnect path.

ep0out: cmd 'Start New Configuration'
ep0out: cmd 'Set Endpoint Transfer Resource'
ep0in: cmd 'Set Endpoint Transfer Resource'
ep1out: cmd 'Set Endpoint Transfer Resource'
...
event (00030601): Suspend [U3]
event (00000101): Reset [U0]
ep0out: req ffffff87e5c9e100 length 0/0 zsI ==> 0
event (00000201): Connection Done [U0]
ep0out: cmd 'Start New Configuration'
ep0out: cmd 'Set Endpoint Transfer Resource'

In addition, if a soft disconnect occurs, EP0 events are still allowed to
process, however, it will stall/restart during the SETUP phase.  The
host is still able to query for the DATA phase, leading to a
xfernotready(DATA) event.  Since none of the SETUP transfer parameters are
populated, the xfernotready is treated as a "wrong direction" error,
leading to a duplicate stall/restart routine.

Add the proper softconnect/connected checks in sequences that are
potentially involved during soft disconnect processing.

Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20220817182359.13550-2-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 197af63f8d05fa5cb8774cbc5f51a43070034a6c..33cee0089609a084f11c3653499189aa7b5022ec 100644 (file)
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -197,7 +197,7 @@ int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
        int                             ret;
 
        spin_lock_irqsave(&dwc->lock, flags);
-       if (!dep->endpoint.desc || !dwc->pullups_connected) {
+       if (!dep->endpoint.desc || !dwc->pullups_connected || !dwc->connected) {
                dev_err(dwc->dev, "%s: can't queue to disabled endpoint\n",
                                dep->name);
                ret = -ESHUTDOWN;
@@ -815,7 +815,7 @@ static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
        int ret = -EINVAL;
        u32 len;
 
-       if (!dwc->gadget_driver || !dwc->connected)
+       if (!dwc->gadget_driver || !dwc->softconnect || !dwc->connected)
                goto out;
 
        trace_dwc3_ctrl_req(ctrl);
@@ -1118,6 +1118,8 @@ static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
 {
        switch (event->status) {
        case DEPEVT_STATUS_CONTROL_DATA:
+               if (!dwc->softconnect || !dwc->connected)
+                       return;
                /*
                 * We already have a DATA transfer in the controller's cache,
                 * if we receive a XferNotReady(DATA) we will ignore it, unless

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7767803056780a4ec870ddf00520c7e5d0774aca..406bd4d1a1b6f083283921685c2e4ed50640326f 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3865,6 +3865,9 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
        u8                      lanes = 1;
        u8                      speed;
 
+       if (!dwc->softconnect)
+               return;
+
        reg = dwc3_readl(dwc->regs, DWC3_DSTS);
        speed = reg & DWC3_DSTS_CONNECTSPD;
        dwc->speed = speed;