This is a note to let you know that I've just added the patch titled
USB:fix USB3 devices behind USB3 hubs not resuming at hibernate thaw
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-next 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 also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 64627388b50158fd24d6ad88132525b95a5ef573 Mon Sep 17 00:00:00 2001
From: Zhengjun Xing <zhengjun.xing@xxxxxxxxxxxxxxx>
Date: Wed, 21 Mar 2018 13:29:42 +0800
Subject: USB:fix USB3 devices behind USB3 hubs not resuming at hibernate thaw
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
USB3 hubs don't support global suspend.
USB3 specification 10.10, Enhanced SuperSpeed hubs only support selective
suspend and resume, they do not support global suspend/resume where the
hub downstream facing ports states are not affected.
When system enters hibernation it first enters freeze process where only
the root hub enters suspend, usb_port_suspend() is not called for other
devices, and suspend status flags are not set for them. Other devices are
expected to suspend globally. Some external USB3 hubs will suspend the
downstream facing port at global suspend. These devices won't be resumed
at thaw as the suspend status flag is not set.
A USB3 removable hard disk connected through a USB3 hub that won't resume
at thaw will fail to synchronize SCSI cache, return “cmd cmplt err -71”
error, and needs a 60 seconds timeout which causing system hang for 60s
before the USB host reset the port for the USB3 removable hard disk to
recover.
Fix this by always calling usb_port_suspend() during freeze for USB3
devices.
Signed-off-by: Zhengjun Xing <zhengjun.xing@xxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/core/generic.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index 83c14dda6300..bc8242bc4564 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -210,8 +210,13 @@ static int generic_suspend(struct usb_device *udev, pm_message_t msg)
if (!udev->parent)
rc = hcd_bus_suspend(udev, msg);
- /* Non-root devices don't need to do anything for FREEZE or PRETHAW */
- else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
+ /*
+ * Non-root USB2 devices don't need to do anything for FREEZE
+ * or PRETHAW. USB3 devices don't support global suspend and
+ * needs to be selectively suspended.
+ */
+ else if ((msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
+ && (udev->speed < USB_SPEED_SUPER))
rc = 0;
else
rc = usb_port_suspend(udev, msg);
--
2.16.2