From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tmnt04.transmode.se (147.175.241.83.in-addr.dgcsystems.net [83.241.175.147]) by ozlabs.org (Postfix) with ESMTP id 7763C67B61 for ; Sun, 26 Nov 2006 22:05:12 +1100 (EST) From: "Joakim Tjernlund" To: "'David Brownell'" , "'Benjamin Herrenschmidt'" Subject: RE: NTP time sync Date: Sun, 26 Nov 2006 12:04:54 +0100 Message-ID: <009a01c7114a$b429f850$020120ac@Jocke> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <200611251522.19900.david-b@pacbell.net> Cc: akpm@osdl.org, 'Alessandro Zummo' , 'Andi Kleen' , 'Linux Kernel Mailing List' , ralf@linux-mips.org, linuxppc-dev@ozlabs.org, lethal@linux-sh.org, paulus@samba.org, kkojima@rr.iij4u.or.jp, davem@davemloft.net, rmk@arm.linux.org.uk List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > -----Original Message----- > From: > linuxppc-dev-bounces+joakim.tjernlund=transmode.se@ozlabs.org > [mailto:linuxppc-dev-bounces+joakim.tjernlund=transmode.se@ozl > abs.org] On Behalf Of David Brownell > Sent: den 26 november 2006 00:22 > To: Benjamin Herrenschmidt > Cc: akpm@osdl.org; Alessandro Zummo; linuxppc-dev@ozlabs.org; > lethal@linux-sh.org; Linux Kernel Mailing List; > ralf@linux-mips.org; Andi Kleen; paulus@samba.org; > rmk@arm.linux.org.uk; davem@davemloft.net; kkojima@rr.iij4u.or.jp > Subject: Re: NTP time sync > > On Thursday 23 November 2006 3:00 am, Benjamin Herrenschmidt wrote: > > > > Couldn't we have a transition period by making the kernel > not rely on > > interrupts ? if the NTP irq code just triggers a work > queue, then all of > > a sudden, all of the RTC drivers can be used and the > latency is small. > > That might well be a good enough solution and is very simple. > > Good point. Of course, one issue is that the NTP sync code all > seems to be platform-specific right now ... just like the code > to set the system time from an RTC at boot (except for the new > RTC framework stuff) and after resume. > > - Dave Looking at rtc-dev.c I don't see a MARJOR number assigned to /dev/rtcN. Seems like it is dynamically allocated to whatever major number that is free. Is that the way it is supposed to be? How do I create a static /dev/rtcN in my /dev directory if the major number isn't fixed? Maybe I am just missing something, feel free to correct me :) Jocke