[ Nguyen/Felipe/Greg: Ported from Linux kernel commit 5b738211fb59 ("usb: dwc3: gadget: Don't send unintended link state change") ]
DCTL.ULSTCHNGREQ is a write-only field. When doing a read-modify-write to DCTL, the driver must make sure that there's no unintended link state change request from whatever is read from DCTL.ULSTCHNGREQ. Set link state change to no-action when the driver writes to DCTL.
Signed-off-by: Venkatesh Yadav Abbarapu venkatesh.abbarapu@amd.com --- drivers/usb/dwc3/gadget.c | 16 +++++++--------- drivers/usb/dwc3/gadget.h | 14 ++++++++++++++ 2 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index eb416b832a..24a2c455b0 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -62,7 +62,7 @@ int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode) return -EINVAL; }
- dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg);
return 0; } @@ -1382,7 +1382,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend) dwc->pullups_connected = false; }
- dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg);
do { reg = dwc3_readl(dwc->regs, DWC3_DSTS); @@ -2047,10 +2047,8 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
reg = dwc3_readl(dwc->regs, DWC3_DCTL); reg &= ~DWC3_DCTL_INITU1ENA; - dwc3_writel(dwc->regs, DWC3_DCTL, reg); - reg &= ~DWC3_DCTL_INITU2ENA; - dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg);
dwc3_disconnect_gadget(dwc); dwc->start_config_issued = false; @@ -2099,7 +2097,7 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
reg = dwc3_readl(dwc->regs, DWC3_DCTL); reg &= ~DWC3_DCTL_TSTCTRL_MASK; - dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg); dwc->test_mode = false;
dwc3_stop_active_transfers(dwc); @@ -2215,11 +2213,11 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc) if (dwc->has_lpm_erratum && dwc->revision >= DWC3_REVISION_240A) reg |= DWC3_DCTL_LPM_ERRATA(dwc->lpm_nyet_threshold);
- dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg); } else { reg = dwc3_readl(dwc->regs, DWC3_DCTL); reg &= ~DWC3_DCTL_HIRD_THRES_MASK; - dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg); }
dep = dwc->eps[0]; @@ -2327,7 +2325,7 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
reg &= ~u1u2;
- dwc3_writel(dwc->regs, DWC3_DCTL, reg); + dwc3_gadget_dctl_write_safe(dwc, reg); break; default: /* do nothing */ diff --git a/drivers/usb/dwc3/gadget.h b/drivers/usb/dwc3/gadget.h index 7806ce59a2..b48ec6b237 100644 --- a/drivers/usb/dwc3/gadget.h +++ b/drivers/usb/dwc3/gadget.h @@ -104,4 +104,18 @@ static inline u32 dwc3_gadget_ep_get_transfer_index(struct dwc3 *dwc, u8 number) return DWC3_DEPCMD_GET_RSC_IDX(res_id); }
+/** + * dwc3_gadget_dctl_write_safe - write to DCTL safe from link state change + * @dwc: pointer to our context structure + * @value: value to write to DCTL + * + * Use this function when doing read-modify-write to DCTL. It will not + * send link state change request. + */ +static inline void dwc3_gadget_dctl_write_safe(struct dwc3 *dwc, u32 value) +{ + value &= ~DWC3_DCTL_ULSTCHNGREQ_MASK; + dwc3_writel(dwc->regs, DWC3_DCTL, value); +} + #endif /* __DRIVERS_USB_DWC3_GADGET_H */