Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   chris.chiu@canonical.com
To:     stern@rowland.harvard.edu, gregkh@linuxfoundation.org,
        m.v.b@runbox.com, hadess@hadess.net
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Chris Chiu <chris.chiu@canonical.com>
Subject: [PATCH v3] USB: Don't set USB_PORT_FEAT_SUSPEND on WD19's Realtek Hub
Date:   Thu, 15 Apr 2021 19:48:56 +0800
Message-Id: <20210415114856.4555-1-chris.chiu@canonical.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Chris Chiu <chris.chiu@canonical.com>

Realtek Hub (0bda:5487) in Dell Dock WD19 sometimes fails to work
after the system resumes from suspend with remote wakeup enabled
device connected:
[ 1947.640907] hub 5-2.3:1.0: hub_ext_port_status failed (err = -71)
[ 1947.641208] usb 5-2.3-port5: cannot disable (err = -71)
[ 1947.641401] hub 5-2.3:1.0: hub_ext_port_status failed (err = -71)
[ 1947.641450] usb 5-2.3-port4: cannot reset (err = -71)

Information of this hub:
T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 10 Spd=480  MxCh= 5
D:  Ver= 2.10 Cls=09(hub  ) Sub=00 Prot=02 MxPS=64 #Cfgs=  1
P:  Vendor=0bda ProdID=5487 Rev= 1.47
S:  Manufacturer=Dell Inc.
S:  Product=Dell dock
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=01 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   1 Ivl=256ms
I:* If#= 0 Alt= 1 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=02 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   1 Ivl=256ms

The failure results from the ETIMEDOUT by chance when turning on
the suspend feature for the target port of the hub. The port
will be unresponsive and placed in unknown state. The hub_activate
invoked during resume will fail to get the port stautus with -EPROTO.
Then all devices connected to the hub will never be found and probed.

The USB_PORT_FEAT_SUSPEND is not really necessary due to the
"global suspend" in USB 2.0 spec. It's only for many hub devices
which don't relay wakeup requests from the devices connected to
downstream ports. For this realtek hub, there's no problem waking
up the system from connected keyboard.

This commit bypasses the USB_PORT_FEAT_SUSPEND for the quirky hub.

Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
---

Changelog:
  v3:
    - Do not mislead usbcore that the quirky hub is really suspended.
      return -EIO for quirky hub instead of doing USB_PORT_FEAT_SUSPEND
    - Revise the commit message
  v2:
    Since the 0bda:5413 is the hub device connects to upstream hub
    0bda:5487, the upstream hub which fails the USB_PORT_FEAT_SUSPEND
    is the target this patch really wants to quirk.
    - Fix the quirk target from the connected hub device to the
      upstream hub
    - Correct the usb info of the target hub in the commit message
    - Revise the description of the quirk

 Documentation/admin-guide/kernel-parameters.txt |  3 +++
 drivers/usb/core/hub.c                          | 10 +++++++---
 drivers/usb/core/quirks.c                       |  5 +++++
 include/linux/usb/quirks.h                      |  3 +++
 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 04545725f187..1bb22a9ea5ba 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5682,6 +5682,9 @@
 					pause after every control message);
 				o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra
 					delay after resetting its port);
+				p = USB_QUIRK_NO_SET_FEAT_SUSPEND (Hub can't
+					handle set-port-feature-suspend request
+					correctly);
 			Example: quirks=0781:5580:bk,0a5c:5834:gij
 
 	usbhid.mousepoll=
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7f71218cc1e5..a73e3931aecd 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3328,9 +3328,13 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 	 * Therefore we will turn on the suspend feature if udev or any of its
 	 * descendants is enabled for remote wakeup.
 	 */
-	else if (PMSG_IS_AUTO(msg) || usb_wakeup_enabled_descendants(udev) > 0)
-		status = set_port_feature(hub->hdev, port1,
-				USB_PORT_FEAT_SUSPEND);
+	else if (PMSG_IS_AUTO(msg) || usb_wakeup_enabled_descendants(udev) > 0) {
+		if (hub->hdev->quirks & USB_QUIRK_NO_SET_FEAT_SUSPEND)
+			status = -EIO;
+		else
+			status = set_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_SUSPEND);
+	}
 	else {
 		really_suspend = false;
 		status = 0;
diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 76ac5d6555ae..9f373579bf9e 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -138,6 +138,9 @@ static int quirks_param_set(const char *value, const struct kernel_param *kp)
 			case 'o':
 				flags |= USB_QUIRK_HUB_SLOW_RESET;
 				break;
+			case 'p':
+				flags |= USB_QUIRK_NO_SET_FEAT_SUSPEND;
+				break;
 			/* Ignore unrecognized flag characters */
 			}
 		}
@@ -406,6 +409,8 @@ static const struct usb_device_id usb_quirk_list[] = {
 
 	/* Realtek hub in Dell WD19 (Type-C) */
 	{ USB_DEVICE(0x0bda, 0x0487), .driver_info = USB_QUIRK_NO_LPM },
+	{ USB_DEVICE(0x0bda, 0x5487), .driver_info =
+			USB_QUIRK_NO_SET_FEAT_SUSPEND },
 
 	/* Generic RTL8153 based ethernet adapters */
 	{ USB_DEVICE(0x0bda, 0x8153), .driver_info = USB_QUIRK_NO_LPM },
diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index 5e4c497f54d6..ac469d446c78 100644
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -72,4 +72,7 @@
 /* device has endpoints that should be ignored */
 #define USB_QUIRK_ENDPOINT_IGNORE		BIT(15)
 
+/* Hub can't handle set-port-feature-suspend request correctly */
+#define USB_QUIRK_NO_SET_FEAT_SUSPEND		BIT(16)
+
 #endif /* __LINUX_USB_QUIRKS_H */
-- 
2.20.1