Am Sonntag, 25. Februar 2007 21:45 schrieb Alfred E. Heggestad:
> hi
>
> I have written a small driver for the C-Media CM109 chipset
> used in USB VoIP phones like the KIP-1000. The source can
> be found here:
>
> http://aeh.db.org/pub/cm109.c
/* allocate usb buffers */
cm109->irq_data = usb_buffer_alloc(udev, USB_PKT_LEN,
GFP_ATOMIC, &cm109->irq_dma);
if (cm109->irq_data == NULL)
goto err;
cm109->ctl_data = usb_buffer_alloc(udev, USB_PKT_LEN,
GFP_ATOMIC, &cm109->ctl_dma);
if (!cm109->ctl_data)
goto err;
cm109->ctl_req = usb_buffer_alloc(udev, sizeof(*(cm109->ctl_req)),
GFP_ATOMIC, &cm109->ctl_req_dma);
if (cm109->ctl_req == NULL)
goto err;
No need for atomic allocations.
static DECLARE_RWSEM(sysfs_rwsema);
A mutex is enough. You never do anything but down_write().
static void input_close(struct input_dev *dev)
{
struct cm109_dev *cmd = dev->private;
usb_kill_urb(cmd->urb_ctl);
usb_kill_urb(cmd->urb_irq);
}
This is a race condition. Due to your special requirement of submitting
the URBs from each other's completion handler the guarantees of usb_kill_urb()
are not strong enough for you. You need to use a flag under a spin_lock.
Regards
Oliver
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