From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
To: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: linuxppc-dev@ozlabs.org, Thomas Gleixner <tglx@linutronix.de>,
Paul Mackerras <paulus@samba.org>,
Realtime Kernel <linux-rt-users@vger.kernel.org>
Subject: Re: [PATCH v2 3/4] Implement clockevents driver for powerpc
Date: Mon, 15 Oct 2007 22:33:46 +0400 [thread overview]
Message-ID: <4713B28A.2060004@ru.mvista.com> (raw)
In-Reply-To: <4713A616.3090103@ru.mvista.com>
Hello, I wrote:
>>@@ -797,6 +796,53 @@ void __init clocksource_init(void)
>> clock->name, clock->mult, clock->shift);
>> }
>>+static int decrementer_set_next_event(unsigned long evt,
>>+ struct clock_event_device *dev)
>>+{
>>+ set_dec(evt);
> I'd use (evt - 1) since the interrupt gets generated at 0xffffffff count,
> not 0 (on classic CPUs). With you removing of the code that compensated for
> the errors, they will accumulate. And no, this wouldn't be enough anyway,
> since on 40x and Book E you'll need to set it for evt anyway, since the
> interrupt happens at 0 count...
What that means is that the off-by-one-clock drift is introduced for
classic CPUs (not 40x or Book E which interrupt at 0). And this has dealt
with months ago in the clockevent driver in the -rt patch. So much for my
efforts...
> NAK the patch.
It's too late for NAKs -- I should've given these patches more attention
(yet I was in hospital for 1.5 months).
WBR, Sergei
WARNING: multiple messages have this Message-ID (diff)
From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
To: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Tony Breeds <tony@bakeyournoodle.com>,
linuxppc-dev@ozlabs.org, Thomas Gleixner <tglx@linutronix.de>,
Paul Mackerras <paulus@samba.org>,
Realtime Kernel <linux-rt-users@vger.kernel.org>
Subject: Re: [PATCH v2 3/4] Implement clockevents driver for powerpc
Date: Mon, 15 Oct 2007 22:33:46 +0400 [thread overview]
Message-ID: <4713B28A.2060004@ru.mvista.com> (raw)
In-Reply-To: <4713A616.3090103@ru.mvista.com>
Hello, I wrote:
>>@@ -797,6 +796,53 @@ void __init clocksource_init(void)
>> clock->name, clock->mult, clock->shift);
>> }
>>+static int decrementer_set_next_event(unsigned long evt,
>>+ struct clock_event_device *dev)
>>+{
>>+ set_dec(evt);
> I'd use (evt - 1) since the interrupt gets generated at 0xffffffff count,
> not 0 (on classic CPUs). With you removing of the code that compensated for
> the errors, they will accumulate. And no, this wouldn't be enough anyway,
> since on 40x and Book E you'll need to set it for evt anyway, since the
> interrupt happens at 0 count...
What that means is that the off-by-one-clock drift is introduced for
classic CPUs (not 40x or Book E which interrupt at 0). And this has dealt
with months ago in the clockevent driver in the -rt patch. So much for my
efforts...
> NAK the patch.
It's too late for NAKs -- I should've given these patches more attention
(yet I was in hospital for 1.5 months).
WBR, Sergei
next prev parent reply other threads:[~2007-10-15 18:33 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-21 3:26 [PATCH v2 1/4] Implement {read,update}_persistent_clock Tony Breeds
2007-09-21 3:26 ` [PATCH v2 2/4] Implement generic time of day clocksource for powerpc machines Tony Breeds
2007-09-21 4:05 ` Daniel Walker
2007-09-21 4:05 ` Daniel Walker
2007-09-21 4:59 ` Paul Mackerras
2007-09-21 4:59 ` Paul Mackerras
2007-09-21 6:43 ` David Gibson
2007-09-21 6:43 ` David Gibson
2007-09-21 4:52 ` Stephen Rothwell
2007-09-21 4:52 ` Stephen Rothwell
2007-09-21 21:35 ` Tony Breeds
2007-09-21 21:35 ` Tony Breeds
2007-09-21 21:35 ` [PATCH v3 " Tony Breeds
2007-09-21 21:35 ` Tony Breeds
2007-10-03 0:48 ` Paul Mackerras
2007-10-03 0:48 ` Paul Mackerras
2007-10-03 4:00 ` Thomas Gleixner
2007-10-03 4:00 ` Thomas Gleixner
2007-09-21 3:26 ` [PATCH v2 4/4] Enable tickless idle and high res timers for powerpc Tony Breeds
2007-09-21 3:26 ` [PATCH v2 3/4] Implement clockevents driver " Tony Breeds
2007-10-15 17:40 ` Sergei Shtylyov
2007-10-15 17:40 ` Sergei Shtylyov
2007-10-15 18:33 ` Sergei Shtylyov [this message]
2007-10-15 18:33 ` Sergei Shtylyov
2007-10-15 23:44 ` Paul Mackerras
2007-10-15 23:44 ` Paul Mackerras
2007-10-17 14:29 ` Sergei Shtylyov
2007-10-17 14:29 ` Sergei Shtylyov
2007-10-18 0:51 ` Paul Mackerras
2007-10-18 0:51 ` Paul Mackerras
2007-10-18 15:11 ` Sergei Shtylyov
2007-10-18 15:11 ` Sergei Shtylyov
2007-10-19 1:53 ` Paul Mackerras
2007-10-19 1:53 ` Paul Mackerras
2007-10-19 12:11 ` Sergei Shtylyov
2007-10-19 12:11 ` Sergei Shtylyov
2007-10-19 12:36 ` Paul Mackerras
2007-10-19 12:36 ` Paul Mackerras
2007-10-19 13:35 ` Sergei Shtylyov
2007-10-19 13:35 ` Sergei Shtylyov
2007-10-24 12:07 ` Sergei Shtylyov
2007-10-24 12:07 ` Sergei Shtylyov
2007-10-24 23:55 ` Paul Mackerras
2007-10-17 14:34 ` Sergei Shtylyov
2007-10-17 14:34 ` Sergei Shtylyov
2007-10-18 0:36 ` Paul Mackerras
2007-10-18 0:36 ` Paul Mackerras
2007-10-18 14:48 ` Sergei Shtylyov
2007-10-18 14:48 ` Sergei Shtylyov
2007-10-19 0:14 ` Paul Mackerras
2007-10-19 0:14 ` Paul Mackerras
2007-10-19 9:22 ` Gabriel Paubert
2007-10-19 9:22 ` Gabriel Paubert
2007-10-19 11:22 ` Paul Mackerras
2007-10-19 11:49 ` Sergei Shtylyov
2007-10-19 11:49 ` Sergei Shtylyov
2007-10-19 12:24 ` Paul Mackerras
2007-10-19 12:24 ` Paul Mackerras
2007-09-26 19:04 ` [PATCH v2 1/4] Implement {read,update}_persistent_clock Steven Rostedt
2007-09-26 19:04 ` Steven Rostedt
2007-09-26 19:39 ` Sergei Shtylyov
2007-09-26 19:39 ` Sergei Shtylyov
2007-09-26 19:44 ` Steven Rostedt
2007-09-26 19:44 ` Steven Rostedt
2007-09-26 19:58 ` Thomas Gleixner
2007-09-26 19:58 ` Thomas Gleixner
2007-10-15 18:05 ` Sergei Shtylyov
2007-10-15 18:05 ` Sergei Shtylyov
2007-10-15 23:46 ` Paul Mackerras
2007-10-15 23:46 ` Paul Mackerras
2007-10-16 1:19 ` Benjamin Herrenschmidt
2007-10-16 1:19 ` Benjamin Herrenschmidt
2007-10-17 12:45 ` Sergei Shtylyov
2007-10-17 12:45 ` Sergei Shtylyov
2007-09-27 1:59 ` Benjamin Herrenschmidt
2007-09-27 1:59 ` Benjamin Herrenschmidt
2007-10-15 18:07 ` Sergei Shtylyov
2007-10-15 18:07 ` Sergei Shtylyov
2007-10-15 23:02 ` Benjamin Herrenschmidt
2007-10-17 15:34 ` Sergei Shtylyov
2007-10-17 15:34 ` Sergei Shtylyov
2007-10-18 14:18 ` Sergei Shtylyov
2007-10-18 14:18 ` Sergei Shtylyov
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