Hi Oliver many thanks for your feedback, see comments inline..
Oliver Neukum wrote: > 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. > ok fixed. I uploaded a new version here: http://aeh.db.org/pub/cm109-v0.2.c > 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. 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 actually turn *off* the buzzer if using the input event API. any ideas? > 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. > I added "struct mutex io_mutex" to my device object. Should this be locked in the USB irq/ctl handlers ? /alfred > Regards > Oliver ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
