On Mon, Feb 25, 2008 at 11:16:24AM -0800, Chetan Karia wrote: > On 25/02/2008, Greg KH <[EMAIL PROTECTED]> wrote: > > On Mon, Feb 25, 2008 at 09:18:12AM -0800, Chetan Karia wrote: > > > On 22/02/2008, Greg KH <[EMAIL PROTECTED]> wrote: > > > > On Fri, Feb 22, 2008 at 05:30:22PM -0800, Chetan Karia wrote: > > > > > On 22/02/2008, Greg KH <[EMAIL PROTECTED]> wrote: > > > > > > On Wed, Feb 20, 2008 at 10:35:48AM -0800, Chetan Karia wrote: > > > > > > > Hello, > > > > > > > > > > > > > > I am kernel newbie and I have a question about usb serial > > driver. I > > > > > > > have a usb to serial driver which exposes 3 virtual serial > > ports > > > > > > > ttyUSB0, ttyUSB1 and ttyUSB2. The endpoint to virtual serial > > port > > > > > > > mapping is like this > > > > > > > ep0 ==> ttyUSB0 > > > > > > > ep1 ==> ttyUSB1 > > > > > > > ep2 ==> ttyUSB2. > > > > > > > > > > > > > > > > > > Which device is this? I think you are talking about the endpoint > > > > > > "pairs" one IN and one OUT per tty, right? > > > > > > > > > > > Yes I am talking about endpoint per one IN and one OUT per tty. > > > > > > > > > > > > But what physical device is this? > > > > > > > This is the sierra wireless device. > > > > > > Usually you use PPP over this kind of connection, by providing two > > read/write ports to it, you have the very large chance of messing up the > > ppp protocol, correct? > > > > What specifically are you trying to do in userspace that you need two > > reads or writes to do that is not working today? > > Alright, here is the entire situation.
Please next time let's not wait for 7 emails to transpire before this comes out, it wastes everyone's time involved... > The sierra device has pair of endpoints (bulk in and bulk out) that > sends the multiplexed protocols data packets ( two protocols data > packets encapsulated in one). Lets call that endpoint pair as EP1. The > one of the multiplexed protocol is DM and other is command and status. > EP1 is attached to ttyUSB1. Our application reads from ttyUSB1 and > ignores DM packets and considers only command and status packets. > However to get DM stream working another application has to read/write > to ttyUSB1 concurrently which is as tricky. Thus, I am trying to setup > another virtual serial port called ttyUSB3 that can read/write to EP1 > concurrently so that we get two duplicate streams. One of the stream > (ttyUSB1) can be used by our existing application and another stream > (ttyUSB3) can be used to set up DM logging.Internally however they > will talk to same endpoint pair EP1. Is it doable? Yes, for something like this, a modification of the sierra driver would be needed to allow for two buffers like this. But, you might want to work with the current developers of the sierra driver, as I'm pretty sure they are working to add this kind of functionality (alternate ways to control the card) to the driver for this very reason. Is there a reason you have not just contacted them already? thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
