From: Oliver Neukum <oliver@neukum.org>
To: Arseniy Lartsev <ars3n@yandex.ru>, USB list <linux-usb@vger.kernel.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: PROBLEM: USB ACM device does not work
Date: Sun, 28 Jun 2009 22:20:49 +0200 [thread overview]
Message-ID: <200906282220.50313.oliver@neukum.org> (raw)
In-Reply-To: <200906282229.35713.ars3n@yandex.ru>
Am Sonntag, 28. Juni 2009 20:29:26 schrieb Arseniy Lartsev:
> I've got a piece of hardware (this one:
> http://masterkit.ru/main/set.php?num=1153) which acts like an USB ACM
> device and is handeled by the cdc_acm module. /dev/ttyACM0 does appear
> but any attempt to write something to the device with a simple
> "echo something >/dev/ttyACM0" fails with "Invalid argument" error.
>
> The reason is that the driver calls usb_submit_urb in acm_start_wb()
> but doesn't set interval in the urb structure, so it remains zero and
> causes usb_submit_urb to return -EINVAL. Reading from device also does
> not work due to the same problem in acm_rx_tasklet().
This is supposed to write to bulk endpoints. There's no reason interval
would need to be specified. Something is very odd. Please post "lsusb -v".
Regards
Oliver
next prev parent reply other threads:[~2009-06-28 20:20 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-28 18:29 PROBLEM: USB ACM device does not work Arseniy Lartsev
2009-06-28 20:20 ` Oliver Neukum [this message]
2009-06-28 20:37 ` Arseniy Lartsev
2009-06-28 20:58 ` Oliver Neukum
2009-06-29 11:43 ` Arseniy Lartsev
2009-06-29 13:07 ` Oliver Neukum
2009-06-29 13:35 ` Arseniy Lartsev
2009-06-30 7:22 ` Oliver Neukum
2009-06-30 20:09 ` Arseniy Lartsev
2009-06-30 21:01 ` Alan Stern
2009-07-01 9:01 ` Arseniy Lartsev
2009-07-01 10:56 ` Oliver Neukum
2009-07-01 11:24 ` Arseniy Lartsev
2009-07-01 11:37 ` Oliver Neukum
2009-07-01 12:27 ` [PATCH] cdc-acm: work around some broken devices Arseniy Lartsev
2009-07-01 13:56 ` Greg KH
2009-07-01 14:03 ` Oliver Neukum
2009-07-01 14:34 ` Alan Stern
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