From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756340Ab0CXQXA (ORCPT ); Wed, 24 Mar 2010 12:23:00 -0400 Received: from web94909.mail.in2.yahoo.com ([203.104.17.168]:21943 "HELO web94909.mail.in2.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752014Ab0CXQW7 convert rfc822-to-8bit (ORCPT ); Wed, 24 Mar 2010 12:22:59 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.in; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=saMCi3Pch8HeKg5kwafErez5Bl0s9L4QzhRptf7PwYcjC0Cv9Xr/6fIlfd28htQmb2f+lzErR67ATaCcz+3SAvNcWvsQjTDmX0Uxpl3FkV3bVu9jpYFiGTeT9cRx7EX/r+Ti4arF1psgU45HirVbn3zDI4gkaOibpGvyyz+BV/w=; Message-ID: <12213.61465.qm@web94909.mail.in2.yahoo.com> X-YMail-OSG: Luo3Dz8VM1mkJIW3TQvPe7Uz01zs0Wp0GG42XJOO1DLy4ss ERq78QN3eX4WDRBIlaWV2T2dqJ6H71_AoDQtjVFYuWAVlmc8.8NVpkW1CO6V rC9zXcZ8IreQ9JmHigmUsbal85a1LWV.1L6a6eJyXDZQbDoq1hsnKxL1EdsJ iMGppAUTXQ3SCkK0ob8KQEp9DQ1bbIYUszUSXO4TwPUYFdEzx3fEJp.Ukiff dxTyRBHtSvr2OSNin61zlfPgNge6S3Wlcudx4ImMlqgp8ayhR..BgZtchq2V azTl6WehV0sR6OHK8Ri1H0iQ- X-Mailer: YahooMailClassic/10.0.8 YahooMailWebService/0.8.100.260964 Date: Wed, 24 Mar 2010 21:52:56 +0530 (IST) From: Pavan Savoy Subject: Re: [PATCH 4/6] drivers:misc: sources for Init manager module To: Marcel Holtmann Cc: Greg KH , PavanSavoy , "alan@lxorguk.ukuu.org.uk" , "linux-kernel@vger.kernel.org" In-Reply-To: <1269447105.11714.117.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --- On Wed, 24/3/10, Marcel Holtmann wrote: > From: Marcel Holtmann > Subject: Re: [PATCH 4/6] drivers:misc: sources for Init manager module > To: "Pavan Savoy" > Cc: "Greg KH" , "PavanSavoy" , "alan@lxorguk.ukuu.org.uk" , "linux-kernel@vger.kernel.org" > Date: Wednesday, 24 March, 2010, 9:41 PM > Hi Pavan, > > > > I wanted to somehow put this in staging because then > it would probably have a thorough architectural review > process. > > Some details about this driver - > > > > 1. This driver will be used by Bluetooth-BlueZ/FM-V4L2 > and GPS (probably character device driver) using the > EXPORTED symbols (-register/_unregister). > > > > 2. Much like the hciattach daemon which maintains > N_HCI bluetooth line discipline, this driver will also have > a User-Space  N_TI_WL Init manager (UIM) maintaining > the Line discipline. > > can you explain why you think this is needed and we can not > interface > this directly. If it is a serial port, what protocol does > it talk? Illustration: The BT driver on top of this ST driver, would create a hci0 interface, when someone does an DEVUP on that interface, the BT driver would then do a st-register - which in-turn would ask the hciattach-like daemon to install the line discipline for it via the sysfs entry. The same concept goes for FM-V4L2 and GPS character driver. The core of the problem is we cannot ask/install/ldisc_put for a line discipline from kernel space. > > > 3. Because of the UIM should know when to > install/uninstall line discipline, the /sys entry is created > a root called UIM (a new kobject) and UIM daemon would write > it's PID to it. > > I don't understand this. This sounds like a broken concept > to me. Yes, I don't feel good about it either. But how do I request for a line discipline from kernel space ? Currently a daemon has to run in user-space to maintain the ldisc, at all times, and I don't want to open TTY @ boot, and install Ldisc (tiocsetd) on it, without BT/FM or GPS core on chip being used - The Power Management team here would beat me up if I do that, and hence the very dumb idea of passing the PID of the daemon via sysfs entry, and the driver sending SIGUSR2 to that PID, daemon doing a tiocsetd upon that signal. > > > 4. As Alan suggested, If I make it self-contained by > pushing number of line disciplines to a slightly larger > number, then would it be OK ? > > Just from a quick look, I think within a few review cycles > this might be > able to get proper upstream inclusion. No idea why bother > with staging > in the first place. Lets do this correctly. > The only reason I wanted this to be in staging was to have sort of continuous review process, and in hope the driver wouldn't be forgotten. > Regards > > Marcel > > > The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/