linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kai-Heng Feng <kai.heng.feng@canonical.com>
To: gregkh@linuxfoundation.org
Cc: mathias.nyman@intel.com, stern@rowland.harvard.edu,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	Kai-Heng Feng <kai.heng.feng@canonical.com>
Subject: [PATCH v2] usb: Allow USB device to be warm reset in suspended state
Date: Wed,  6 Nov 2019 14:27:10 +0800	[thread overview]
Message-ID: <20191106062710.29880-1-kai.heng.feng@canonical.com> (raw)

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>
---
v2:
- Update kerneldoc.

 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 05a2d51bdbe0..eaf28eed51b0 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5849,7 +5849,7 @@ 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
@@ -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


             reply	other threads:[~2019-11-06  6:27 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-06  6:27 Kai-Heng Feng [this message]
2019-11-06 15:07 ` [PATCH v2] usb: Allow USB device to be warm reset in suspended state Alan Stern

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191106062710.29880-1-kai.heng.feng@canonical.com \
    --to=kai.heng.feng@canonical.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=mathias.nyman@intel.com \
    --cc=stern@rowland.harvard.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).