Date: Thu, 08 Nov 2001 13:30:44 -0700 From: "Justin T. Gibbs" <gibbs@scsiguy.com> To: "John S. Bucy" <bucy@ece.cmu.edu> Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: aic7xxx u160? Message-ID: <200111082030.fA8KUiY64275@aslan.scsiguy.com> In-Reply-To: Your message of "Thu, 08 Nov 2001 15:23:30 EST." <20011108152330.M5611@joy.pdl.cmu.edu>
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>
>static struct ahc_syncrate ahc_syncrates[]
>
>in aic7xxx.c does not seem to contain an entry for 160mb/sec.
The top most entry is for 160MB/s:
/* ultra2 fast/ultra period rate */
{ 0x42, 0x000, 9, "80.0" },
The REQ/ACK rate at 160MB/s is 80MHz. Two bytes are transferred
per REQ/ACK pair.
>Am I missing something or does the aic7xxx driver need to be made aware
>that 160 is a legal syncrate? I'm playing with 29160s -- one in
>target mode and the other as initiator -- connected between the
>internal LVD connectors and I can't get them to negotiate at 160.
>Will these cards not do ultra 160 in a 32bit/33mhz PCI slot?
The inquiry data for you emulated target does not have the SPI3
"Double Transition Clocking Supported" bit set. CAM will not even
attempt to negotiate speeds above Ultra2 (40MHz Wide == 80MB/s) with
such a device. See the code in cam_xpt.c:xpt_set_transfer_settings().
--
Justin
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