usb: dwc2: drd: fix soft connect when gadget is unconfigured

commit 32fde84362c40961726a5c91f35ad37355ccc0c6 upstream.

When the gadget driver hasn't been (yet) configured, and the cable is
connected to a HOST, the SFTDISCON gets cleared unconditionally, so the
HOST tries to enumerate it.
At the host side, this can result in a stuck USB port or worse. When
getting lucky, some dmesg can be observed at the host side:
 new high-speed USB device number ...
 device descriptor read/64, error -110

Fix it in drd, by checking the enabled flag before calling
dwc2_hsotg_core_connect(). It will be called later, once configured,
by the normal flow:
- udc_bind_to_driver
 - usb_gadget_connect
   - dwc2_hsotg_pullup
     - dwc2_hsotg_core_connect

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/1644999135-13478-1-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index cb9059a8444b5a601e56e141dfe87c7793181760..71e62b3081dbb2c5571d7669e5759a9c2b60aeef 100644 (file)
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -1417,6 +1417,7 @@ void dwc2_hsotg_core_connect(struct dwc2_hsotg *hsotg);
 void dwc2_hsotg_disconnect(struct dwc2_hsotg *dwc2);
 int dwc2_hsotg_set_test_mode(struct dwc2_hsotg *hsotg, int testmode);
 #define dwc2_is_device_connected(hsotg) (hsotg->connected)
+#define dwc2_is_device_enabled(hsotg) (hsotg->enabled)
 int dwc2_backup_device_registers(struct dwc2_hsotg *hsotg);
 int dwc2_restore_device_registers(struct dwc2_hsotg *hsotg, int remote_wakeup);
 int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg);
@@ -1453,6 +1454,7 @@ static inline int dwc2_hsotg_set_test_mode(struct dwc2_hsotg *hsotg,
                                           int testmode)
 { return 0; }
 #define dwc2_is_device_connected(hsotg) (0)
+#define dwc2_is_device_enabled(hsotg) (0)
 static inline int dwc2_backup_device_registers(struct dwc2_hsotg *hsotg)
 { return 0; }
 static inline int dwc2_restore_device_registers(struct dwc2_hsotg *hsotg,

diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
index aa6eb76f64ddc0ea78b39bf53451005fa7bc87a1..36f2c38416e5ec4c2b942c0a49db3571ee9d04fd 100644 (file)
--- a/drivers/usb/dwc2/drd.c
+++ b/drivers/usb/dwc2/drd.c
@@ -109,8 +109,10 @@ static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
                already = dwc2_ovr_avalid(hsotg, true);
        } else if (role == USB_ROLE_DEVICE) {
                already = dwc2_ovr_bvalid(hsotg, true);
-               /* This clear DCTL.SFTDISCON bit */
-               dwc2_hsotg_core_connect(hsotg);
+               if (dwc2_is_device_enabled(hsotg)) {
+                       /* This clear DCTL.SFTDISCON bit */
+                       dwc2_hsotg_core_connect(hsotg);
+               }
        } else {
                if (dwc2_is_device_mode(hsotg)) {
                        if (!dwc2_ovr_bvalid(hsotg, false))