From: Wesley Cheng <quic_wcheng@xxxxxxxxxxx> [ Upstream commit 0066472de157439d58454f4a55786f1045ea5681 ] 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@xxxxxxxxxxxx> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220316011358.3057-1-quic_wcheng@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Stable-dep-of: 040f2dbd2010 ("usb: dwc3: gadget: Avoid duplicate requests to enable Run/Stop") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/usb/dwc3/core.c | 2 +- drivers/usb/dwc3/core.h | 2 ++ drivers/usb/dwc3/gadget.c | 11 +++++++++++ 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index f4655665a1b5..a9c49b2ce511 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -227,7 +227,7 @@ 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 a93c61bc5a7d..f320b989abd2 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1422,6 +1422,8 @@ 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 079919b85d87..b95fc2ae8074 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2088,6 +2088,17 @@ 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); } -- 2.35.1
