usb: dwc2: also exit clock_gating when stopping udc while suspended

[ Upstream commit af076a41f8a28faf9ceb9dd2d88aef2c202ef39a ]

It is possible that the gadget will be disabled, while the udc is
suspended. When enabling the udc in that case, the clock gating
will not be enabled again. Leaving the phy unclocked. Even when the
udc is not enabled, connecting this powered but not clocked phy leads
to enumeration errors on the host side.

To ensure that the clock gating will be in an valid state, we ensure
that the clock gating will be enabled before stopping the udc.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Link: https://lore.kernel.org/r/20250417-dwc2_clock_gating-v1-1-8ea7c4d53d73@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index ce20c06a902531f19ac550972640abd71f5a312f..c0db3c52831a2da6c337aca91b08d37390d81401 100644 (file)
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -4601,6 +4601,12 @@ static int dwc2_hsotg_udc_stop(struct usb_gadget *gadget)
        if (!hsotg)
                return -ENODEV;
 
+       /* Exit clock gating when driver is stopped. */
+       if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_NONE &&
+           hsotg->bus_suspended && !hsotg->params.no_clock_gating) {
+               dwc2_gadget_exit_clock_gating(hsotg, 0);
+       }
+
        /* all endpoints should be shutdown */
        for (ep = 1; ep < hsotg->num_of_eps; ep++) {
                if (hsotg->eps_in[ep])