UPSTREAM: usb: dwc3: Issue core soft reset before enabling run/stop It is recommended by the Synopsis databook to issue a DCTL.CSftReset when reconnecting from a device-initiated disconnect routine. This resolves issues with enumeration during fast composition switching cases, which result in an unknown device on the host. Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com> Link: https://lore.kernel.org/r/20220316011358.3057-1-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Bug: 230843866 (cherry picked from commit 0066472de157439d58454f4a55786f1045ea5681) Change-Id: Idcfbb43e844c22cdfcb1362177e9c1a8e9a7e18e Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index cb514a3..ca0966b 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c
@@ -114,8 +114,6 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode) dwc->current_dr_role = mode; } -static int dwc3_core_soft_reset(struct dwc3 *dwc); - static void __dwc3_set_mode(struct work_struct *work) { struct dwc3 *dwc = work_to_dwc(work); @@ -260,7 +258,7 @@ u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type) * dwc3_core_soft_reset - Issues core soft reset and PHY reset * @dwc: pointer to our context structure */ -static int dwc3_core_soft_reset(struct dwc3 *dwc) +int dwc3_core_soft_reset(struct dwc3 *dwc) { u32 reg; int retries = 1000;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 44f1364..d52d4ecf 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h
@@ -1539,6 +1539,8 @@ bool dwc3_has_imod(struct dwc3 *dwc); int dwc3_event_buffers_setup(struct dwc3 *dwc); void dwc3_event_buffers_cleanup(struct dwc3 *dwc); +int dwc3_core_soft_reset(struct dwc3 *dwc); + #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE) int dwc3_host_init(struct dwc3 *dwc); void dwc3_host_exit(struct dwc3 *dwc);
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 93759e8..ae99f021 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c
@@ -2520,6 +2520,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) dwc->ev_buf->length; } } else { + /* + * In the Synopsys DWC_usb31 1.90a programming guide section + * 4.1.9, it specifies that for a reconnect after a + * device-initiated disconnect requires a core soft reset + * (DCTL.CSftRst) before enabling the run/stop bit. + */ + spin_unlock_irqrestore(&dwc->lock, flags); + dwc3_core_soft_reset(dwc); + spin_lock_irqsave(&dwc->lock, flags); + + dwc3_event_buffers_setup(dwc); __dwc3_gadget_start(dwc); }