Date: Tue, 27 Jun 2000 16:13:10 -0700 From: Shih-Nan Huang <shuang@alteon.com> To: Joy Ganguly <joy@niksun.com> Cc: openfw <openfw@alteon.com>, freebsd-hackers <freebsd-hackers@freebsd.org> Subject: Re: Tigon firmware... Message-ID: <39593506.D85B73A9@alteon.com> References: <39592A14.23E1EDF0@falcon.niksun.com>
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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
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