This is a note to let you know that I've just added the patch titled
USB: cdc-wdm: cannot use dev_printk when device is gone
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also will be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 6b0b79d38806481c1c8fffa7c5842f3c83679a42 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <[email protected]>
Date: Wed, 9 May 2012 13:53:22 +0200
Subject: USB: cdc-wdm: cannot use dev_printk when device is gone
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
We cannot dereference a removed USB interface for
dev_printk. Use pr_debug instead where necessary.
Flush errors are expected if device is unplugged and are
therefore best ingored at this point.
Move the kill_urbs() call in wdm_release with dev_dbg()
for the non disconnect, as we know it has already been
called if WDM_DISCONNECTING is set. This does not
actually fix anything, but keeps the code more consistent.
Cc: Oliver Neukum <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/class/cdc-wdm.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 7652275..90bc916 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -533,7 +533,9 @@ static int wdm_flush(struct file *file, fl_owner_t id)
struct wdm_device *desc = file->private_data;
wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
- if (desc->werr < 0)
+
+ /* cannot dereference desc->intf if WDM_DISCONNECTING */
+ if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
dev_err(&desc->intf->dev, "Error in flush path: %d\n",
desc->werr);
@@ -625,12 +627,13 @@ static int wdm_release(struct inode *inode, struct file
*file)
mutex_unlock(&desc->wlock);
if (!desc->count) {
- dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
- kill_urbs(desc);
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
+ kill_urbs(desc);
desc->manage_power(desc->intf, 0);
} else {
- dev_dbg(&desc->intf->dev, "%s: device gone - cleaning
up\n", __func__);
+ /* must avoid dev_printk here as desc->intf is invalid
*/
+ pr_debug(KBUILD_MODNAME " %s: device gone - cleaning
up\n", __func__);
cleanup(desc);
}
}
--
1.7.10.1.362.g242cab3
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