[PATCH 5.15 024/177] usb: dwc3: core: Only handle soft-reset in DCTL

From: Greg Kroah-Hartman
Date: Wed May 04 2022 - 13:13:24 EST


From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

commit f4fd84ae0765a80494b28c43b756a95100351a94 upstream.

Make sure not to set run_stop bit or link state change request while
initiating soft-reset. Register read-modify-write operation may
unintentionally start the controller before the initialization completes
with its previous DCTL value, which can cause initialization failure.

Fixes: f59dcab17629 ("usb: dwc3: core: improve reset sequence")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/6aecbd78328f102003d40ccf18ceeebd411d3703.1650594792.git.Thinh.Nguyen@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -275,7 +275,8 @@ static int dwc3_core_soft_reset(struct d

reg = dwc3_readl(dwc->regs, DWC3_DCTL);
reg |= DWC3_DCTL_CSFTRST;
- dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+ reg &= ~DWC3_DCTL_RUN_STOP;
+ dwc3_gadget_dctl_write_safe(dwc, reg);

/*
* For DWC_usb31 controller 1.90a and later, the DCTL.CSFRST bit