Am Freitag, 4. September 2009 19:42:47 schrieb Paul Martin: > On Fri, Sep 04, 2009 at 12:58:40PM +0200, Oliver Neukum wrote: > > Am Donnerstag, 3. September 2009 23:59:02 schrieb Andrew Morton: > > > > # cat /dev/ttyACM0 > > > > cat: /dev/ttyACM0: Input/output error > > > > > > > > This device works in 2.6.30, but is broken in 2.6.31-rc1 and > > > > following. > > > > Please provide lsusb -v? Anything in the syslog? Please do an strace. > > I'd like to know whether it errors in open or read. > > It was attached to the original bug. > > http://bugzilla.kernel.org/attachment.cgi?id=22952 > > From the strace: > .. > open("/dev/ttyACM0", O_RDONLY|O_LARGEFILE) = -1 EIO (Input/output error) > .. OK, please apply the included debugging patch, change "#undef DEBUG" in cdc-acm.c to "#define DEBUG", recompile and post dmesg. Regards Oliver -- commit e1b8b513bcba5313efa8b1637c5d9490a1944236 Author: Oliver Neukum <oliver@xxxxxxxxxx> Date: Fri Sep 4 19:53:04 2009 +0200 usb:cdc-acm: additional debugging output diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 2bfc41e..d4e6c05 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -610,6 +610,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) tasklet_schedule(&acm->urb_task); rv = tty_port_block_til_ready(&acm->port, tty, filp); + if (rv < 0) + dbg("tty_port_block_til_ready returned %d", rv); done: mutex_unlock(&acm->mutex); err_out: -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
