[PATCH 6.12 189/567] usb: dwc3: keep susphy enabled during exit to avoid controller faults

Greg Kroah-Hartman
2026-01-06T17:24:39Z

From: Udipto Goswami <udipto.goswami@oss.qualcomm.com>

commit e1003aa7ec9eccdde4c926bd64ef42816ad55f25 upstream.

On some platforms, switching USB roles from host to device can trigger
controller faults due to premature PHY power-down. This occurs when the
PHY is disabled too early during teardown, causing synchronization
issues between the PHY and controller.

Keep susphy enabled during dwc3_host_exit() and dwc3_gadget_exit()
ensures the PHY remains in a low-power state capable of handling
required commands during role switch.

Cc: stable <stable@kernel.org>
Fixes: 6d735722063a ("usb: dwc3: core: Prevent phy suspend during init")
Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Udipto Goswami <udipto.goswami@oss.qualcomm.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://patch.msgid.link/20251126054221.120638-1-udipto.goswami@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/dwc3/gadget.c | 2 +-
drivers/usb/dwc3/host.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -4793,7 +4793,7 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
if (!dwc->gadget)
return;

- dwc3_enable_susphy(dwc, false);
+ dwc3_enable_susphy(dwc, true);
usb_del_gadget(dwc->gadget);
dwc3_gadget_free_endpoints(dwc);
usb_put_gadget(dwc->gadget);
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -223,7 +223,7 @@ void dwc3_host_exit(struct dwc3 *dwc)
if (dwc->sys_wakeup)
device_init_wakeup(&dwc->xhci->dev, false);

- dwc3_enable_susphy(dwc, false);
+ dwc3_enable_susphy(dwc, true);
platform_device_unregister(dwc->xhci);
dwc->xhci = NULL;
}