From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id F17FE21A0480E for ; Sun, 9 Apr 2017 21:39:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1491799164; x=1523335164; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=nOXoBpIR3Af3xOFhfeuuuIJIPW+Q7DMoLPPgpDn3Zwc=; b=C/ycLVxCNfpVQfjLf4Xn1Y33LtcXBqt5EdzaOPgcDnqqp8gHDyRHgFlq H3th6KQpiaInM0UdjuKi/yX2lue5ug==; Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Apr 2017 21:39:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,180,1488873600"; d="scan'208";a="1117625837" Received: from fmsmsx104.amr.corp.intel.com ([10.18.124.202]) by orsmga001.jf.intel.com with ESMTP; 09 Apr 2017 21:39:24 -0700 Received: from fmsmsx113.amr.corp.intel.com (10.18.116.7) by fmsmsx104.amr.corp.intel.com (10.18.124.202) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 9 Apr 2017 21:39:23 -0700 Received: from shsmsx103.ccr.corp.intel.com (10.239.4.69) by FMSMSX113.amr.corp.intel.com (10.18.116.7) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 9 Apr 2017 21:39:23 -0700 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.193]) by SHSMSX103.ccr.corp.intel.com ([169.254.4.117]) with mapi id 14.03.0319.002; Mon, 10 Apr 2017 12:39:21 +0800 From: "Tian, Feng" To: Arka Sharma , "edk2-devel@lists.01.org" CC: "Tian, Feng" Thread-Topic: [edk2] NvmExpressDxe TimerEvent frequency Thread-Index: AQHSsOuPoI2PoIcYEUS3g0X/oaOF1aG+BqgQ Date: Mon, 10 Apr 2017 04:39:21 +0000 Message-ID: <7F1BAD85ADEA444D97065A60D2E97EE5699E343C@SHSMSX101.ccr.corp.intel.com> References: In-Reply-To: Accept-Language: zh-CN, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] MIME-Version: 1.0 Subject: Re: NvmExpressDxe TimerEvent frequency X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Apr 2017 04:39:25 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Yes. For example, old platforms usually use 50ms as timer interval. So at such p= latforms, even the code is programming to use 1 ms timer, the actual trigge= r time interval is 50ms. Thanks Feng -----Original Message----- From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Arka= Sharma Sent: Sunday, April 9, 2017 12:41 PM To: edk2-devel@lists.01.org Subject: [edk2] NvmExpressDxe TimerEvent frequency Hi, UEFI Driver Write Guide section 5.1.6 says "UEFI system firmware uses a har= dware timer interrupt to measure time. These. These time measurements are used to determine when enough time has passed to sign= al a timer event programmed with SetTimer(). In most systems, the timer int= errupt is generated every 10 ms to 50 ms, but the UEFI Specification does n= ot require any specific interrupt rate. This lack of specificity means that= a periodic timer programmed with a period much smaller than 10 ms may only= be signaled every 10 ms to 50 ms.". So in case of NvmExpressDxe the Privat= e->TimerEvent is set with 1 ms, so the frequency of the routine ProcessAsyn= cTaskList might be more than 1 ms as per the frequency of the timer interru= pt ? Regards, Arka _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel