staging: gdm72xx: Fix spinlock recursion on gdm_usb_send_complete

This patch fixes a spinlock recursion bug on several call sites of
gdm_usb_send_complete by not calling spin_lock_irqsave on
urb->context->tx_cxt->lock when the lock has already been acquired.

Signed-off-by: Ben Chan <benchan@chromium.org>
Cc: Sage Ahn <syahn@gctsemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ben Chan 2012-06-06 23:01:26 -07:00 committed by Greg Kroah-Hartman
parent 7dd80eb925
commit dd13c86b0d

View file

@ -270,7 +270,7 @@ static void release_usb(struct usbwm_dev *udev)
}
}
static void gdm_usb_send_complete(struct urb *urb)
static void gdm_usb_send_complete_impl(struct urb *urb, bool need_lock)
{
struct usb_tx *t = urb->context;
struct tx_cxt *tx = t->tx_cxt;
@ -282,7 +282,8 @@ static void gdm_usb_send_complete(struct urb *urb)
if (urb->status == -ECONNRESET)
return;
spin_lock_irqsave(&tx->lock, flags);
if (need_lock)
spin_lock_irqsave(&tx->lock, flags);
if (t->callback)
t->callback(t->cb_data);
@ -296,7 +297,18 @@ static void gdm_usb_send_complete(struct urb *urb)
else
free_tx_struct(t);
spin_unlock_irqrestore(&tx->lock, flags);
if (need_lock)
spin_unlock_irqrestore(&tx->lock, flags);
}
static void gdm_usb_send_complete(struct urb *urb)
{
gdm_usb_send_complete_impl(urb, true);
}
static void gdm_usb_send_complete_no_lock(struct urb *urb)
{
gdm_usb_send_complete_impl(urb, false);
}
static int gdm_usb_send(void *priv_dev, void *data, int len,
@ -411,7 +423,7 @@ static int gdm_usb_send(void *priv_dev, void *data, int len,
send_fail:
t->callback = NULL;
gdm_usb_send_complete(t->urb);
gdm_usb_send_complete_no_lock(t->urb);
spin_unlock_irqrestore(&tx->lock, flags);
return ret;
}
@ -540,7 +552,7 @@ static void do_pm_control(struct work_struct *work)
if (ret) {
t->callback = NULL;
gdm_usb_send_complete(t->urb);
gdm_usb_send_complete_no_lock(t->urb);
}
}
}
@ -742,7 +754,7 @@ static int k_mode_thread(void *arg)
if (ret) {
t->callback = NULL;
gdm_usb_send_complete(t->urb);
gdm_usb_send_complete_no_lock(t->urb);
}
}