From: Venkatesh Yadav Abbarapu <venkatesh.abbar...@amd.com>
[ 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.abbar...@amd.com>
---
Not to be merged, I know Marek does not apply any patches to DWC3.
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 eb416b832aad..24a2c455b0a4 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 7806ce59a27f..b48ec6b2372f 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 */
--
2.34.1
