From: David Brownell <david-b@pacbell.net>
To: mgross@linux.intel.com
Cc: Greg KH <greg@kroah.com>, lkml <linux-kernel@vger.kernel.org>,
linux-rt-users@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: Real time USB2Serial devices and behaivor
Date: Thu, 27 Mar 2008 12:48:40 -0700 [thread overview]
Message-ID: <200803271248.40519.david-b@pacbell.net> (raw)
In-Reply-To: <20080326164946.GA17928@linux.intel.com>
On Wednesday 26 March 2008, mark gross wrote:
> On Wed, Mar 26, 2008 at 09:27:28AM -0700, Greg KH wrote:
> > Give up and use a "real" serial port, you'll have better luck :)
>
> but its getting very hard to find real serial ports any more :(
I happened across this the other day, and saved the URL since
the price was relatively sane ... $15 vs the $60 I saw at
another site, although ISTR Fry's used to have them at $5:
http://www.wrighthobbies.net/catalog/index.php?cPath=47
Yeah, I know. "It's getting very hard to find real PCI slots
any more." :(
It seems like some companies (notably *cough* Intel) are
on a little jihad to get rid of serial ports...
I'd think that in a controlled environment (fixed set of
USB connections) USB should be able to meet fairly chosen
"real time" latency ceilings. The stack probably needs a
few semantic updates to make it happen -- e.g. URB completions
are issued in_irq() -- but it shouldn't be insurmountable.
- Dave
next prev parent reply other threads:[~2008-03-27 19:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-26 15:25 Real time USB2Serial devices and behaivor mark gross
2008-03-26 16:27 ` Greg KH
2008-03-26 16:49 ` mark gross
2008-03-26 23:24 ` Greg KH
2008-03-27 2:58 ` Alan Stern
2008-03-27 4:13 ` Greg KH
2008-03-27 19:48 ` David Brownell [this message]
2008-03-27 21:00 ` Lennart Sorensen
2008-03-27 21:08 ` David Brownell
2008-03-28 13:38 ` Lennart Sorensen
2008-04-03 14:26 ` Ming Lei
2008-04-03 14:45 ` Peter Zijlstra
2008-04-03 15:52 ` Greg KH
2008-04-03 6:24 ` Jon Masters
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