From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxim Levitsky Subject: Re: [3/6] 2.6.21-rc4: known regressions Date: Fri, 30 Mar 2007 01:29:27 +0200 Message-ID: <200703300129.27474.maximlevitsky@gmail.com> References: <200703282327.56132.maximlevitsky@gmail.com> <200703291533.38002.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200703291533.38002.david-b@pacbell.net> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: David Brownell Cc: Jeff Chua , linux-acpi@vger.kernel.org, jgarzik@pobox.com, linux-pm@lists.linux-foundation.org, gregkh@suse.de, Linux Kernel Mailing List , Adrian Bunk , linux-ide@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, Thomas Gleixner , "Eric W. Biederman" , Jens Axboe , "Michael S. Tsirkin" , Andrew Morton , Linus Torvalds , Ingo Molnar List-Id: linux-ide@vger.kernel.org On Friday 30 March 2007 00:33:35 David Brownell wrote: > On Wednesday 28 March 2007 2:27 pm, Maxim wrote: > > On Wednesday 28 March 2007 22:59:26 David Brownell wrote: > = > > When HPET is active it eats RTC IRQ, > = > Only when HPET timers 0 and 1 are set up for "Legacy Replacement Mode". > In the more sensible "Standard Mode", they have their own IRQs. > = > = > > So the only way out is to emulate RTC using HPET, > > It is done this way in old rtc driver, rtc-cmos should do the same. > = > No. Patches like > = > http://marc.info/?l=3Dlinux-kernel&m=3D117219531503973&w=3D2 > = > should be merged (I hope they're in the 2.6.22 queue!), making > HPET run in "Standard Mode" so that HPET can stop sticking its > fingers in code where they don't belong. > = > = > > I am also planning to add support of HPET and suspend/resume > > for rtc-cmos, but I didn't start this yet. = > = > It's already got suspend/resume support, and in the 2.6.22 queue > are RTC framework updates which will let the RTC framework replace > a lot more platform-specific RTC support. (Platform changes can come > later, where they're needed. ARM for example doesn't need any.) > = > Once HPET stops using "Legacy Replacement Mode" you won't need to > touch anything in the RTC stack (except maybe the legacy char/rtc.c > driver, removing HPET stuff). > = > The open issue with suspend/resume support in rtc-cmos relates to > how ACPI wakeup alarms should trigger. I've not made time to test > those patches. > = > - Dave > = Hi, It is not that simple, Only in legacy replacement mode HPET can be put on IRQ0 (and sadly IRQ8) At least this is true on some systems, on mine for example = On my system first 2 hpet timers can only be assigned to IRQ21-23 and third to ether IRQ11, IRQ21-IRQ23 Or in legacy replacement mode first is assigned IRQ0 and second IRQ8 this will make it difficult to use it as a clockevents source Not to mention the fact that current code assumes that BIOS assigned IRQs = to all timers which is not true on my system. I have brand new intel DG965 motherboard. What is wrong with relying on HPET to provide RTC IRQ ? Best regards, Maxim Levitsky