From: Greg KH <gregkh@suse.de>
To: Raju Rameshwar Uprade <rajsingh@ncra.tifr.res.in>
Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: pl2303_ttyUSB0 userspace application not able to control RTS line
Date: Tue, 5 Oct 2010 06:33:12 -0700 [thread overview]
Message-ID: <20101005133312.GF3548@suse.de> (raw)
In-Reply-To: <20101005104403.M28756@admin-gateway.ncra.tifr.res.in>
On Tue, Oct 05, 2010 at 04:33:16PM +0530, Raju Rameshwar Uprade wrote:
> Hi,
> I am using a prolific tech USB-to-serial converter on linux kernel version 2.6.35.
> I wrote a userspace program to enable/disable RTS line which is working fine with
> standard serial port like ttyS0 and ttyS1.
>
> But when I used the USB-to-serial port (ttyUSB0) to enable/disable the RTS line,ttyUSB0
> is not able to do that as well as some times gives
>
> pl2303_ttyUSB0 : pl2303_open-failed submitting read urb -error 22.
Is this your "modified" driver?
I don't see that error in the kernel log below at all.
What kernel version is this?
And are you sure that your device actually has the RTS lines connected?
I have seen a number of these devices that do not bring those lines from
the chip to the rs232 connection.
You really might want to go purchase a "real" usb to serial converter
that works properly, the pl2303 devices do not fit that category.
good luck,
greg k-h
next prev parent reply other threads:[~2010-10-05 13:36 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-13 9:17 Regarding USB-to-Serial device driver Raju Rameshwar Uprade
2010-09-13 13:56 ` Alan Stern
2010-09-13 15:48 ` Greg KH
2010-09-14 6:11 ` Raju Rameshwar Uprade
2010-09-14 13:19 ` Greg KH
2010-09-22 5:32 ` Regarding USB-to-serial " Raju Rameshwar Uprade
2010-09-22 14:56 ` Greg KH
2010-09-23 10:15 ` Raju Rameshwar Uprade
2010-09-23 14:02 ` Greg KH
2010-09-28 9:21 ` Raju Rameshwar Uprade
2010-09-28 11:30 ` Greg KH
2010-09-28 11:56 ` Raju Rameshwar Uprade
2010-09-28 12:07 ` Greg KH
2010-10-04 4:33 ` Raju Rameshwar Uprade
2010-10-05 11:03 ` pl2303_ttyUSB0 userspace application not able to control RTS line Raju Rameshwar Uprade
2010-10-05 13:33 ` Greg KH [this message]
2010-10-06 4:14 ` Raju Rameshwar Uprade
2010-10-06 4:30 ` Greg Oliver
2010-10-06 5:01 ` Raju Rameshwar Uprade
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