From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tilman Schmidt Subject: Re: [PATCH] Add the ability to layer another driver over the serial driver Date: Wed, 13 Dec 2006 01:21:32 +0100 Message-ID: <457F478C.2010702@imap.cc> References: <4533B8FB.5080108@mvista.com> <20061210201438.tilman@imap.cc> <457CB32A.2060804@mvista.com> <20061211102016.43e76da2@localhost.localdomain> <457D8E35.9050706@imap.cc> <20061211174004.5605fb47@localhost.localdomain> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigA9A3F79F6EA252CA77252C51" Return-path: In-Reply-To: <20061211174004.5605fb47@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org To: Alan Cc: Corey Minyard , Guennadi Liakhovetski , linux-serial@vger.kernel.org, Linux Kernel , Hansjoerg Lipp , Russell Doty List-Id: linux-serial@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigA9A3F79F6EA252CA77252C51 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Am 11.12.2006 18:40 schrieb Alan: > On Mon, 11 Dec 2006 17:58:29 +0100 > Tilman Schmidt wrote: >=20 >> On Mon, 11 Dec 2006 10:20:16 +0000, Alan wrote: >>> This looks wrong. You already have a kernel interface to serial drive= rs. >>> It is called a line discipline. We use it for ppp, we use it for slip= , we >>> use it for a few other things such as attaching sync drivers to some >>> devices. >> I was under the impression that line disciplines need a user space >> process to open the serial device and push them onto it.=20 >=20 > Yes that is correct. You need a way for the user to tell you which port= > to use and to the permission and usage management for it anyway (as wel= l > as load the module and configure settings), so this seems quite > reasonable. I'm afraid I'm not familiar with Linux' SLIP implementation. So there's a line discipline called "slip" which, when pushed onto a serial port, registers as a network device, right? How does it get - and stay - pushed? Is there a daemon process which opens the serial port, pushes the line discipline onto it, and then just sleeps, keeping the serial port open so that the line discipline stays put? Can you point me to the source for such a daemon for reference? What I am actually looking for is a way to port an existing driver which directly programs an i8250 serial port, to cooperate more cleanly with the existing serial port drivers of Linux (and, at the same time, shed the dependency on the specific serial port hardware.) If that requires a permanently running (or sleeping) userspace daemon, then so be it. (Although I admit I'd rather do without.) Thanks Tilman --=20 Tilman Schmidt E-Mail: tilman@imap.cc Bonn, Germany Diese Nachricht besteht zu 100% aus wiederverwerteten Bits. Unge=F6ffnet mindestens haltbar bis: (siehe R=FCckseite) --------------enigA9A3F79F6EA252CA77252C51 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3rc1 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFf0eMMdB4Whm86/kRAjTKAJ4x7QFA3ra01lXKy5ah+6gp0GMHkgCeMq9t hcjtJ5NXvmSzqWcH2S0wDL0= =1cFk -----END PGP SIGNATURE----- --------------enigA9A3F79F6EA252CA77252C51--