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@xxxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 05a2d51bdbe0..f0194fdbc9b8 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5877,8 +5877,7 @@ 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;
--
2.17.1
