[PATCH] fix hso soft-lockup

From: Antti Kaijanmäki
Date: Thu Oct 22 2009 - 04:43:08 EST


Fix soft-lockup in hso.c which is triggered on SMP machine when
modem is removed while file descriptor(s) under /dev are still open:

old version called kref_put() too early which resulted in destroying
hso_serial and hso_device objects which were still used later on.

Also fix driver debug routines (not compiled in by default).
---
drivers/net/usb/hso.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index fa4e581..539642a 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2,6 +2,7 @@
*
* Driver for Option High Speed Mobile Devices.
*
+ * Copyright (C) 2009 Antti KaijanmÃki <antti.kaijanmaki@xxxxxxxxxxx>
* Copyright (C) 2008 Option International
* Filip Aben <f.aben@xxxxxxxxxx>
* Denis Joseph Barrow <d.barow@xxxxxxxxxx>
@@ -378,7 +379,7 @@ static void dbg_dump(int line_count, const char *func_name, unsigned char *buf,
}

#define DUMP(buf_, len_) \
- dbg_dump(__LINE__, __func__, buf_, len_)
+ dbg_dump(__LINE__, __func__, (unsigned char*)buf_, len_)

#define DUMP1(buf_, len_) \
do { \
@@ -1363,7 +1364,7 @@ static void hso_serial_close(struct tty_struct *tty, struct file *filp)
/* reset the rts and dtr */
/* do the actual close */
serial->open_count--;
- kref_put(&serial->parent->ref, hso_serial_ref_free);
+
if (serial->open_count <= 0) {
serial->open_count = 0;
spin_lock_irq(&serial->serial_lock);
@@ -1383,6 +1384,8 @@ static void hso_serial_close(struct tty_struct *tty, struct file *filp)
usb_autopm_put_interface(serial->parent->interface);

mutex_unlock(&serial->parent->mutex);
+
+ kref_put(&serial->parent->ref, hso_serial_ref_free);
}

/* close the requested serial port */
@@ -1527,7 +1530,7 @@ static void tiocmget_intr_callback(struct urb *urb)
dev_warn(&usb->dev,
"hso received invalid serial state notification\n");
DUMP(serial_state_notification,
- sizeof(hso_serial_state_notifation))
+ sizeof(struct hso_serial_state_notification));
} else {

UART_state_bitmap = le16_to_cpu(serial_state_notification->
--
1.6.3.3

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