patch usb-r8a66597-hcd-fix-removed-from-an-attached-hub.patch added to gregkh-2.6 tree

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This is a note to let you know that I've just added the patch titled

    Subject: usb: r8a66597-hcd: fix removed from an attached hub

to my gregkh-2.6 tree.  Its filename is

    usb-r8a66597-hcd-fix-removed-from-an-attached-hub.patch

This tree can be found at 
    http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/


>From shimoda.yoshihiro@xxxxxxxxxxx  Tue Mar 16 13:38:39 2010
From: Yoshihiro Shimoda <shimoda.yoshihiro@xxxxxxxxxxx>
Date: Tue, 16 Mar 2010 12:29:35 +0900
Subject: usb: r8a66597-hcd: fix removed from an attached hub
To: Paul Mundt <lethal@xxxxxxxxxxxx>, "Pietrek, Markus" <Markus.Pietrek@xxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>, linux-sh@xxxxxxxxxxxxxxx, USB list <linux-usb@xxxxxxxxxxxxxxx>
Message-ID: <4B9EFB1F.3090201@xxxxxxxxxxx>


fix the problem that when a USB hub is attached to the r8a66597-hcd and
a device is removed from that hub, it's likely that a kernel panic follows.

Reported-by: Markus Pietrek <Markus.Pietrek@xxxxxxxxxx>
Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@xxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/usb/host/r8a66597-hcd.c |   16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -418,7 +418,7 @@ static u8 alloc_usb_address(struct r8a66
 
 /* this function must be called with interrupt disabled */
 static void free_usb_address(struct r8a66597 *r8a66597,
-			     struct r8a66597_device *dev)
+			     struct r8a66597_device *dev, int reset)
 {
 	int port;
 
@@ -430,7 +430,13 @@ static void free_usb_address(struct r8a6
 	dev->state = USB_STATE_DEFAULT;
 	r8a66597->address_map &= ~(1 << dev->address);
 	dev->address = 0;
-	dev_set_drvdata(&dev->udev->dev, NULL);
+	/*
+	 * Only when resetting USB, it is necessary to erase drvdata. When
+	 * a usb device with usb hub is disconnect, "dev->udev" is already
+	 * freed on usb_desconnect(). So we cannot access the data.
+	 */
+	if (reset)
+		dev_set_drvdata(&dev->udev->dev, NULL);
 	list_del(&dev->device_list);
 	kfree(dev);
 
@@ -1069,7 +1075,7 @@ static void r8a66597_usb_disconnect(stru
 	struct r8a66597_device *dev = r8a66597->root_hub[port].dev;
 
 	disable_r8a66597_pipe_all(r8a66597, dev);
-	free_usb_address(r8a66597, dev);
+	free_usb_address(r8a66597, dev, 0);
 
 	start_root_hub_sampling(r8a66597, port, 0);
 }
@@ -2085,7 +2091,7 @@ static void update_usb_address_map(struc
 				spin_lock_irqsave(&r8a66597->lock, flags);
 				dev = get_r8a66597_device(r8a66597, addr);
 				disable_r8a66597_pipe_all(r8a66597, dev);
-				free_usb_address(r8a66597, dev);
+				free_usb_address(r8a66597, dev, 0);
 				put_child_connect_map(r8a66597, addr);
 				spin_unlock_irqrestore(&r8a66597->lock, flags);
 			}
@@ -2228,7 +2234,7 @@ static int r8a66597_hub_control(struct u
 			rh->port |= (1 << USB_PORT_FEAT_RESET);
 
 			disable_r8a66597_pipe_all(r8a66597, dev);
-			free_usb_address(r8a66597, dev);
+			free_usb_address(r8a66597, dev, 1);
 
 			r8a66597_mdfy(r8a66597, USBRST, USBRST | UACT,
 				      get_dvstctr_reg(port));

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