On Tue, Sep 08, 2009 at 02:38:53PM +0200, Oliver Neukum wrote:
> Am Montag, 7. September 2009 21:59:37 schrieb Paul Martin:
> > > This is extremely interesting, as it points to a general failure.
> > > But I cannot see how the return value comes about. To double check
> > > could you commented out those lines in cdc-acm.c and try again?
> > >
> > > rv = tty_port_block_til_ready(&acm->port, tty, filp);
> > > if (rv < 0)
> > > dbg("tty_port_block_til_ready returned %d", rv);
> >
> > This works. I'm on Linus 2.6.31-rc9 with the following modifiacation:
>
> OK, please test this patch.
That works. Just to confirm, this is how git diff shows things:
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 2bfc41e..765264f 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -57,6 +57,7 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
+#include <linux/serial.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
@@ -609,7 +610,11 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
acm->throttle = 0;
tasklet_schedule(&acm->urb_task);
+ set_bit(ASYNCB_INITIALIZED, &acm->port.flags);
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:
--
Paul Martin <pm@xxxxxxxxxx>
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