From a52e4f2dff413b58c7200e89bb6540bd995e1269 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 29 Jan 2026 10:15:34 +0800 Subject: [PATCH] usb: dwc2: fix resume failure if dr_mode is host commit 13b1f8e25bfd1 ("usb: dwc2: Force mode optimizations") removed the dwc2_force_mode(hsotg, true) in dwc2_force_dr_mode() if dr_mode is host. But this brings a bug: the controller fails to resume back as host, further debugging shows that the controller is resumed as peripheral. The reason is dwc2_force_dr_mode() missed the host mode forcing, and when resuming from s2ram, GINTSTS is 0 by default, dwc2_is_device_mode in dwc2_resume() misreads this as the controller is in peripheral mode. Fix the resume failure by adding back the dwc2_force_mode(hsotg, true). Then an obvious question is: why this bug hasn't been observed and fixed for about six years? There are two resons: most dwc2 platforms set the dr_mode as otg; Some platforms don't have suspend & resume support yet. Fixes: 13b1f8e25bfd1 ("usb: dwc2: Force mode optimizations") Cc: stable Signed-off-by: Jisheng Zhang Link: https://patch.msgid.link/20260129021534.10411-1-jszhang@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc2/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c index c3d24312db0fe..f375c5185bfe2 100644 --- a/drivers/usb/dwc2/core.c +++ b/drivers/usb/dwc2/core.c @@ -578,6 +578,7 @@ void dwc2_force_dr_mode(struct dwc2_hsotg *hsotg) { switch (hsotg->dr_mode) { case USB_DR_MODE_HOST: + dwc2_force_mode(hsotg, true); /* * NOTE: This is required for some rockchip soc based * platforms on their host-only dwc2. -- 2.47.3