Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933622AbbFJJLd (ORCPT ); Wed, 10 Jun 2015 05:11:33 -0400 Received: from ns.horizon.com ([71.41.210.147]:52581 "HELO ns.horizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S933586AbbFJJLY (ORCPT ); Wed, 10 Jun 2015 05:11:24 -0400 Date: 10 Jun 2015 04:55:35 -0400 Message-ID: <20150610085535.4750.qmail@ns.horizon.com> From: "George Spelvin" To: adrian.hunter@intel.com, linux@horizon.com Subject: Re: Discussion: quick_pit_calibrate is slow Cc: ak@linux.intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org, luto@amacapital.net, mingo@kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org In-Reply-To: <5577F193.70702@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 690 Lines: 17 Adrian Hunter wrote: > On 10/06/15 10:08, George Spelvin wrote: >> The 8254 timer latches the msbyte when the lsbyte is read >> and returns the latched value on the next read > Are you sure about? The docs I've read don't seem to say that. You're right; I musy have been thinking about the write side which does this, or some other hardware. Anyway, the counter latch command exists and can be used for the purpose. So the idea still works. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/