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. Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx> --- Changes in v3: - Removed change from RFC series and placed into its own patch. Previous patches: https://lore.kernel.org/linux-usb/20220203080017.27339-1-quic_wcheng@xxxxxxxxxxx/ drivers/usb/dwc3/core.c | 4 +--- drivers/usb/dwc3/core.h | 2 ++ drivers/usb/dwc3/gadget.c | 11 +++++++++++ 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 18adddfba3da..02d10e1cb774 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -115,8 +115,6 @@ 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); @@ -261,7 +259,7 @@ 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 eb9c1efced05..86e27afef6c5 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1530,6 +1530,8 @@ 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 a0c883f19a41..448ff6cb9c22 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2544,6 +2544,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) dwc->ev_buf->length; } } else { + /* + * In the Synopsis DesignWare Cores USB3 Databook Rev. 1.90a + * 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); }
