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Date:   Wed, 29 Sep 2021 15:48:22 -0700
Message-Id: <20210929224823.556943-1-rajatja@google.com>
Mime-Version: 1.0
Subject: [PATCH 1/2] usb: hub: Mark root hubs on removable devices, as removable.
From:   Rajat Jain <rajatja@google.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        Rajat Jain <rajatja@google.com>,
        Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Chris Chiu <chris.chiu@canonical.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     levinale@google.com, bleung@google.com, rajatxjain@gmail.com,
        jsbarnes@google.com, pmalani@google.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Currently all usb root hubs are always marked as DEVICE_REMOVABLE_UNKNOWN
unconditionally. Let us try to help the users to identify the removable
root hubs, by checking the device on which the root hub sits. If the base
(parent) device on which the root hub sits, is removable (e.g. on
thunderbolt docks), then the roothub is also marked as removable.

Signed-off-by: Rajat Jain <rajatja@google.com>
---
 drivers/usb/core/hub.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 86658a81d284..45d1c81b121d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2440,8 +2440,16 @@ static void set_usb_port_removable(struct usb_device *udev)
 
 	dev_set_removable(&udev->dev, DEVICE_REMOVABLE_UNKNOWN);
 
-	if (!hdev)
+	if (!hdev) {
+		/*
+		 * If the root hub sits on a removable device, mark the root hub
+		 * removable as well. This helps with the USB root hubs sitting
+		 * on the thunderbolt docks.
+		 */
+		if (udev->dev.parent && dev_is_removable(udev->dev.parent))
+			dev_set_removable(&udev->dev, DEVICE_REMOVABLE);
 		return;
+	}
 
 	hub = usb_hub_to_struct_hub(udev->parent);
 
-- 
2.33.0.685.g46640cef36-goog