[PATCH 1/2] usb: mtu3: allow system suspend during active gadget connection

[Fei Shao]

When operating in gadget mode connected to a USB host, system suspend
fails with -EBUSY because active peripheral connections block suspend
entry.

Fix this by restricting the -EBUSY check to runtime autosuspend
(PMSG_IS_AUTO). For system suspend (!PMSG_IS_AUTO), perform soft
disconnect to disconnect from the bus and allow MAC sleep.

Fixes: 427c66422e14 ("usb: mtu3: support suspend/resume for device mode")
Signed-off-by: Fei Shao <fshao at chromium.org>
---

 drivers/usb/mtu3/mtu3_core.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/mtu3/mtu3_core.c b/drivers/usb/mtu3/mtu3_core.c
index 66dbfe1705d5..a40bf5bad2d5 100644
--- a/drivers/usb/mtu3/mtu3_core.c
+++ b/drivers/usb/mtu3/mtu3_core.c
@@ -1037,9 +1037,14 @@ int ssusb_gadget_suspend(struct ssusb_mtk *ssusb, pm_message_t msg)
 	if (!mtu->gadget_driver)
 		return 0;
 
-	if (mtu->connected)
+	/* Prevent runtime suspend when active connection exists */
+	if (mtu->connected && PMSG_IS_AUTO(msg))
 		return -EBUSY;
 
+	/* Perform soft disconnect for system suspend */
+	if (mtu->softconnect && !PMSG_IS_AUTO(msg))
+		mtu3_dev_on_off(mtu, 0);
+
 	mtu3_dev_suspend(mtu);
 	synchronize_irq(mtu->irq);
 
@@ -1055,5 +1060,9 @@ int ssusb_gadget_resume(struct ssusb_mtk *ssusb, pm_message_t msg)
 
 	mtu3_dev_resume(mtu);
 
+	/* Restore soft connect for system resume */
+	if (mtu->softconnect && !PMSG_IS_AUTO(msg))
+		mtu3_dev_on_off(mtu, 1);
+
 	return 0;
 }
-- 
2.55.0.rc0.799.gd6f94ed593-goog