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From:   AceLan Kao <acelan.kao@canonical.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Harry Pan <harry.pan@intel.com>,
        David Heinzelmann <heinzelmann.david@gmail.com>,
        Andrey Konovalov <andreyknvl@google.com>,
        Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
        Mathieu Malaterre <malat@debian.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] usb: hub: move resume delay at the head of all USB access functions
Date:   Fri, 20 Dec 2019 10:59:17 +0800
Message-Id: <20191220025917.11886-1-acelan.kao@canonical.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

usb_control_msg() function should be called after the resume delay, or
you'll encounter the below errors sometime.
After the issue happens, have to re-plug the USB cable to recover.

[ 837.483573] hub 2-3:1.0: hub_ext_port_status failed (err = -71)
[ 837.490889] hub 2-3:1.0: hub_ext_port_status failed (err = -71)
[ 837.506780] usb 2-3-port4: cannot disable (err = -71)

Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
---
 drivers/usb/core/hub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f229ad6952c0..2fb2816b0d38 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3522,6 +3522,7 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 		}
 	}
 
+	msleep(USB_RESUME_TIMEOUT);
 	usb_lock_port(port_dev);
 
 	/* Skip the initial Clear-Suspend step for a remote wakeup */
@@ -3544,7 +3545,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 		/* drive resume for USB_RESUME_TIMEOUT msec */
 		dev_dbg(&udev->dev, "usb %sresume\n",
 				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
-		msleep(USB_RESUME_TIMEOUT);
 
 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
 		 * stop resume signaling.  Then finish the resume
-- 
2.17.1