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patch "usb: dwc2: drd: fix soft connect when gadget is unconfigured" added to usb-linus

PATCH [email protected] 1 participant 1 message Feb 17, 2022

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Stable branch USB DesignWare USB2 DRD IP driver
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This is a note to let you know that I've just added the patch titled

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

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 32fde84362c40961726a5c91f35ad37355ccc0c6 Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier <[email protected]>
Date: Wed, 16 Feb 2022 09:12:15 +0100
Subject: usb: dwc2: drd: fix soft connect when gadget is unconfigured

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 <[email protected]>
Signed-off-by Fabrice Gasnier <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/usb/dwc2/core.h | 2 ++
 drivers/usb/dwc2/drd.c  | 6 ++++--
 2 files changed, 6 insertions(+), 2 deletions(-)
drivers/usb/dwc2/core.h +2 -0
index 8a63da3ab39d..88c337bf564f 100644
@@ -1418,6 +1418,7 @@ 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);

@@ -1454,6 +1455,7 @@ 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,
drivers/usb/dwc2/drd.c +4 -2
index 1b39c4776369..d8d6493bc457 100644
@@ -130,8 +130,10 @@ 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))
Signature · 1 line
2.35.1