Am Mittwoch, 28. Februar 2007 01:29 schrieb Alfred E. Heggestad:
> Hi Oliver
>
> an updated version of the CM109 driver is available:
> (this time as a complete patch)
>
> http://aeh.db.org/patch/cm109-20070227.patch
+ spin_lock(&dev->submit_lock);
+ /* ask for a response */
+ if (!dev->disconnecting)
+ ret = usb_submit_urb(dev->urb_irq, GFP_KERNEL);
must be GFP_ATOMIC
+ if (urb->status) {
+ if (-ESHUTDOWN == urb->status)
+ return;
Test for being killed by usb_kill_urb() or you might report
bogus key presses
+ out:
+ ret = usb_submit_urb(dev->urb_ctl, GFP_KERNEL);
+ if (ret)
GFP_ATOMIC
+ case '1':
+ on = 1;
+ break;
+
+ default:
+ goto out;
+ }
Shouldn't default report an error?
> Oliver Neukum wrote:
> > Am Montag, 26. Februar 2007 23:58 schrieb Alfred E. Heggestad:
> >
> >>> static DECLARE_RWSEM(sysfs_rwsema);
> >>>
> >>> A mutex is enough. You never do anything but down_write().
> >>>
> >> ok that can be fixed. but I am not sure yet how to use the sysfs
> >> interface. at the moment the external buzzer is activated via
> >> doing "echo 1 > /sys/.../buzzer" so that is write only as you
> >> say. But in the future we might want to read/write the EEPROM
> >> via the sysfs interface.
> >
> > Nevertheless a simple mutex will do. There's no need to worry
> > about contention here.
> >
>
> OK, code is now using mutex.
>
>
> >> ideally I would like to use a more standard user interface
> >> for the buzzer, like SND_BELL/SND_TONE. I added some code
> >> in input_ev() for triggering the buzzer, but unfortunately
> >> it crashes the whole box .. also I am not sure how to
> >
> > How does it crash? Any oops report?
> >
>
> turning buzzer on/off from sysfs interface works fine. But when
> the same function is called from the input_ev() event handler,
> it will start the buzzer, and hang the whole machine with two
> LEDs flashing, nothing in the logs..
+#if 0
+ /* TODO crashes the kernel - use better locking ? */
+ buzz(dev, 1);
+#else
This is the code for buzzing? I should have noticed earlier.
You cannot use usb_control_msg() in interrupt. Use an URB.
> should the same be done in urb_irq_callback() ?
Yes.
Regards
Oliver
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