From owner-freebsd-hackers Tue Jun 27 16:13:36 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from dfw7-1.relay.mail.uu.net (dfw7-1.relay.mail.uu.net [199.171.54.106]) by hub.freebsd.org (Postfix) with ESMTP id 565AA37BEE8 for ; Tue, 27 Jun 2000 16:13:31 -0700 (PDT) (envelope-from shuang@alteon.com) Received: from dogbert.alteon.com by dfw7sosrv11.alter.net with SMTP (peer crosschecked as: alteon.com [208.200.21.146]) id QQivlk09372; Tue, 27 Jun 2000 23:13:14 GMT Received: from sharks.alteon.com by dogbert.alteon.com via smtpd (for mail.uu.net [199.171.54.106]) with SMTP; 27 Jun 2000 23:13:16 UT Received: from madrone.acteon.com by alteon.com (8.9.1b+Sun/SMI-SVR4) id QAA27331; Tue, 27 Jun 2000 16:13:12 -0700 (PDT) Received: from alteon.com (localhost [127.0.0.1]) by madrone.acteon.com (8.8.8+Sun/8.8.8) with ESMTP id QAA01854; Tue, 27 Jun 2000 16:13:11 -0700 (PDT) Message-ID: <39593506.D85B73A9@alteon.com> Date: Tue, 27 Jun 2000 16:13:10 -0700 From: Shih-Nan Huang X-Mailer: Mozilla 4.72 [en] (X11; U; SunOS 5.6 sun4u) X-Accept-Language: en-US MIME-Version: 1.0 To: Joy Ganguly Cc: openfw , freebsd-hackers Subject: Re: Tigon firmware... References: <39592A14.23E1EDF0@falcon.niksun.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hi Joy, Current Tigon firmware utilizes a feature provided by the DMA write engine to update the receive buffer consumer automatically. If the TG_DMA_STATE_UPDATE_RX_BUF_CONS bit (b19) is set in the DMA write state register for a DMA operation, the DMA write engine will update the receive buffer consumer to the local NIC DMA address prior to DMA starting. --shihnan Joy Ganguly wrote: > hi all, > > I have been looking into the Tigon firmware code and i am totalyy > puzzled about this: there is no place in the code where > trp->local_mem_conf.rx_buf_consumer is incremented. (except in > h_mac_rx_comp_nohost() which is not called) The tigon documentation says > that it should be incremented by the firmware after the frames have been > dma'd into the host. But h_dma_wr_assist() never does that. Setting a > watchpoint on this register i saw that the register changes when the > "dma write assist producer" register is updated in q_dma_to_host(). Isnt > this strange??.....or am i missing something?? can anybody explain?? > > thanx in advance > > joy To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message