On 3/15/2022 5:28 PM, Thinh Nguyen wrote: > Wesley Cheng wrote: >> 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://urldefense.com/v3/__https://lore.kernel.org/linux-usb/20220203080017.27339-1-quic_wcheng@xxxxxxxxxxx/__;!!A4F2R9G_pg!OjNviLgYSUvXpUWpeTDiI6OVuwjW2kjQpACAYYo5MdI09GClnUHLGFjuoMrtquF8Qe9X$ >> >> 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 Hi Thinh, Thanks for the review. > > It's "Synopsys". Version 1.90a is for DWC_usb31 controller. > Ah, I need to get the incorrect spelling out of my head! :) >> + * 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. > > Just want to note that we're skipping some controller initialization on > soft-reset here. But it's probably fine because the global registers > don't get reset on soft reset. Just need to make sure that the registers > that do get reset get reinitialized on __dwc3_gadget_start(). > >> + */ >> + 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); >> } >> > > It's a little awkward because dwc3 also issues soft-reset during driver > probe. Pullup() is called during driver bindings. So soft-reset is > called multiple times. I don't have a better solution at the moment, but > I don't see a problem with it either. > Correct...this would mainly help w/ the soft connect/disconnect situations. Will fixup the typos and resend. > After fixing the typos, > > Reviewed-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> > > Thanks, > Thinh Thanks Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
