On Thu, 2013-07-25 at 18:53 +0300, Oleksii Shevchuk wrote:
Thank you,
could you try the attached patch?
Regards
Oliver
>From 0b46b7c8cd1747470d7ed874b3a130090d4d7d3c Mon Sep 17 00:00:00 2001
From: Oliver Neukum <[email protected]>
Date: Mon, 5 Aug 2013 09:13:51 +0200
Subject: [PATCH] cdc-wdm: fix race between interrupt handler and tasklet
Both could want to submit the same URB. Some checks of the flag
intended to prevent that were missing.
Signed-off-by: Oliver Neukum <[email protected]>
---
drivers/usb/class/cdc-wdm.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 8a230f0..d3318a0 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -209,6 +209,7 @@ skip_error:
static void wdm_int_callback(struct urb *urb)
{
int rv = 0;
+ int responding;
int status = urb->status;
struct wdm_device *desc;
struct usb_cdc_notification *dr;
@@ -262,8 +263,8 @@ static void wdm_int_callback(struct urb *urb)
spin_lock(&desc->iuspin);
clear_bit(WDM_READ, &desc->flags);
- set_bit(WDM_RESPONDING, &desc->flags);
- if (!test_bit(WDM_DISCONNECTING, &desc->flags)
+ responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
+ if (!responding && !test_bit(WDM_DISCONNECTING, &desc->flags)
&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
rv = usb_submit_urb(desc->response, GFP_ATOMIC);
dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
@@ -685,16 +686,20 @@ static void wdm_rxwork(struct work_struct *work)
{
struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
unsigned long flags;
- int rv;
+ int rv = 0;
+ int responding;
spin_lock_irqsave(&desc->iuspin, flags);
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
spin_unlock_irqrestore(&desc->iuspin, flags);
} else {
+ responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
- rv = usb_submit_urb(desc->response, GFP_KERNEL);
+ if (!responding)
+ rv = usb_submit_urb(desc->response, GFP_KERNEL);
if (rv < 0 && rv != -EPERM) {
spin_lock_irqsave(&desc->iuspin, flags);
+ clear_bit(WDM_RESPONDING, &desc->flags);
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
schedule_work(&desc->rxwork);
spin_unlock_irqrestore(&desc->iuspin, flags);
--
1.8.3.1
