From: Chunfeng Yun <chunfeng.yun@mediatek.com>
Date: Wed, 12 May 2021 02:07:38 +0000 (+0800)
Subject: usb: core: hub: fix race condition about TRSMRCY of resume
X-Git-Tag: v4.4.269~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e4620fee76562b05cc1ae670817c8bbdf2d9eb4;p=thirdparty%2Fkernel%2Fstable.git

usb: core: hub: fix race condition about TRSMRCY of resume

commit 975f94c7d6c306b833628baa9aec3f79db1eb3a1 upstream.

This may happen if the port becomes resume status exactly
when usb_port_resume() gets port status, it still need provide
a TRSMCRY time before access the device.

CC: <stable@vger.kernel.org>
Reported-by: Tianping Fang <tianping.fang@mediatek.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20210512020738.52961-1-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c422b4df97e8c..6e2bf3e69a0ad 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3430,9 +3430,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 		 * sequence.
 		 */
 		status = hub_port_status(hub, port1, &portstatus, &portchange);
-
-		/* TRSMRCY = 10 msec */
-		msleep(10);
 	}
 
  SuspendCleared:
@@ -3447,6 +3444,9 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 				usb_clear_port_feature(hub->hdev, port1,
 						USB_PORT_FEAT_C_SUSPEND);
 		}
+
+		/* TRSMRCY = 10 msec */
+		msleep(10);
 	}
 
 	if (udev->persist_enabled && hub_is_superspeed(hub->hdev))