From e76b3bf7654c3c94554c24ba15a3d105f4006c80 Mon Sep 17 00:00:00 2001

From: Kai-Heng Feng <kai.heng.feng@canonical.com>

Date: Wed, 6 Nov 2019 14:27:10 +0800

Subject: [PATCH] usb: Allow USB device to be warm reset in suspended state

Git-commit: e76b3bf7654c3c94554c24ba15a3d105f4006c80

Patch-mainline: v5.5-rc1

References: bsc#1051510

On Dell WD15 dock, sometimes USB ethernet cannot be detected after plugging

cable to the ethernet port, the hub and roothub get runtime resumed and

runtime suspended immediately:

...

[  433.315169] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0

[  433.315204] usb usb4: usb auto-resume

[  433.315226] hub 4-0:1.0: hub_resume

[  433.315239] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10202e2, return 0x10343

[  433.315264] usb usb4-port1: status 0343 change 0001

[  433.315279] xhci_hcd 0000:3a:00.0: clear port1 connect change, portsc: 0x10002e2

[  433.315293] xhci_hcd 0000:3a:00.0: Get port status 4-2 read: 0x2a0, return 0x2a0

[  433.317012] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.

[  433.422282] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343

[  433.422307] usb usb4-port1: do warm reset

[  433.422311] usb 4-1: device reset not allowed in state 8

[  433.422339] hub 4-0:1.0: state 7 ports 2 chg 0002 evt 0000

[  433.422346] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343

[  433.422356] usb usb4-port1: do warm reset

[  433.422358] usb 4-1: device reset not allowed in state 8

[  433.422428] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 0 status  = 0xf0002e2

[  433.422455] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 1 status  = 0xe0002a0

[  433.422465] hub 4-0:1.0: hub_suspend

[  433.422475] usb usb4: bus auto-suspend, wakeup 1

[  433.426161] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.

[  433.466209] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.510204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.554051] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.598235] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.642154] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.686204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.730205] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.774203] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.818207] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.862040] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting

[  433.862053] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.

[  433.862077] xhci_hcd 0000:3a:00.0: xhci_suspend: stopping port polling.

[  433.862096] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001

[  433.862312] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_suspend: 0

[  433.862445] xhci_hcd 0000:3a:00.0: PME# enabled

[  433.902376] xhci_hcd 0000:3a:00.0: restoring config space at offset 0xc (was 0x0, writing 0x20)

[  433.902395] xhci_hcd 0000:3a:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100403)

[  433.902490] xhci_hcd 0000:3a:00.0: PME# disabled

[  433.902504] xhci_hcd 0000:3a:00.0: enabling bus mastering

[  433.902547] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001

[  433.902649] pcieport 0000:00:1b.0: PME: Spurious native interrupt!

[  433.902839] xhci_hcd 0000:3a:00.0: Port change event, 4-1, id 3, portsc: 0xb0202e2

[  433.902842] xhci_hcd 0000:3a:00.0: resume root hub

[  433.902845] xhci_hcd 0000:3a:00.0: handle_port_status: starting port polling.

[  433.902877] xhci_hcd 0000:3a:00.0: xhci_resume: starting port polling.

[  433.902889] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.

[  433.902891] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0

[  433.902919] usb usb4: usb wakeup-resume

[  433.902942] usb usb4: usb auto-resume

[  433.902966] hub 4-0:1.0: hub_resume

...

As Mathias pointed out, the hub enters Cold Attach Status state and

requires a warm reset. However usb_reset_device() bails out early when

the device is in suspended state, as its callers port_event() and

hub_event() don't always resume the device.

Since there's nothing wrong to reset a suspended device, allow

usb_reset_device() to do so to solve the issue.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Acked-by: Alan Stern <stern@rowland.harvard.edu>

Cc: stable <stable@vger.kernel.org>

Link: https://lore.kernel.org/r/20191106062710.29880-1-kai.heng.feng@canonical.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/usb/core/hub.c | 5 ++---

 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c

index fdcfa85b5b12..1709895387b9 100644

--- a/drivers/usb/core/hub.c

+++ b/drivers/usb/core/hub.c

@@ -5840,7 +5840,7 @@ static int usb_reset_and_verify_device(struct usb_device *udev)

 /**

  * usb_reset_device - warn interface drivers and perform a USB port reset

- * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)

+ * @udev: device to reset (not in NOTATTACHED state)

  *

  * Warns all drivers bound to registered interfaces (using their pre_reset

  * method), performs the port reset, and then lets the drivers know that

@@ -5868,8 +5868,7 @@ int usb_reset_device(struct usb_device *udev)

 	struct usb_host_config *config = udev->actconfig;

 	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);

-	if (udev->state == USB_STATE_NOTATTACHED ||

-			udev->state == USB_STATE_SUSPENDED) {

+	if (udev->state == USB_STATE_NOTATTACHED) {

 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",

 				udev->state);

 		return -EINVAL;

-- 

2.16.4