From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jesse Huang" Subject: Re: [PATCH 2/6] IP100A Fix Tx pause bug Date: Tue, 22 Aug 2006 09:17:08 +0800 Message-ID: <00bd01c6c588$afdedbc0$4964a8c0@icplus.com.tw> References: <1155841445.4532.10.camel@localhost.localdomain> <44E5A425.8020200@pobox.com> Cc: , , Return-path: Received: from msr34.hinet.net ([168.95.4.134]:65449 "EHLO msr34.hinet.net") by vger.kernel.org with ESMTP id S932070AbWHVBUN (ORCPT ); Mon, 21 Aug 2006 21:20:13 -0400 To: "Jeff Garzik" Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org ----- Original Message ----- From: "Jeff Garzik" To: "Jesse Huang" Cc: ; ; Sent: Friday, August 18, 2006 7:27 PM Subject: Re: [PATCH 2/6] IP100A Fix Tx pause bug (1) >> + iowrite8(127, ioaddr + TxDMAPollPeriod); >> + > > what does the value 127 represent? 127 is polling period of Tx DMA to watch if there any packet need to send. The 127 means 127*320ns. (2) > DownCounter should not be written unconditionally. Consider shared > interrupts, where sundance performs no work, and handled==0. DownCount is a the register that we can use for timer interrupt. When the value of DownCount from 1 count down to 0 , IP100A will issue an interrupt.