Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 16 Oct 2008 15:48:50 -0700
From:      steve@Watt.COM (Steve Watt)
To:        hackers@freebsd.org
Subject:   Re: [Doubt] Can a PCI device communicate with another PCI or other
Message-ID:  <200810162248.m9GMmocw007400@wattres.watt.com>
In-Reply-To: <e6a0706a0810161130i6a3820fexf3afdbf28f81bd31@mail.gmail.com>
References:  <e6a0706a0810141132n1a1d1a9cn4a50ffc727640e13@mail.gmail.com> <20081015160522.04A824FEE1E@xroff.net>

next in thread | previous in thread | raw e-mail | index | archive | help
In <e6a0706a0810161130i6a3820fexf3afdbf28f81bd31@mail.gmail.com> mboxindia@gmail.com wrote:
>I think a PCI device can communicate with another PCI device directly
>without the intervention of the CPU.

Absolutely.  Happens a fair amount in embedded networking systems (among
others).

The host is responsible for enumeration and resource assignment, but once
that's complete, any device on the bus can see all others.  Whether that's
useful depends rather heavily on the devices on the bus, obviously.

TANSTAAFL applies, though, in that multiple initiators must be careful not
to step on each others' accesses.

-- 
Steve Watt KD6GGD  PP-ASEL-IA          ICBM: 121W 56' 57.5" / 37N 20' 15.3"
 Internet: steve @ Watt.COM                      Whois: SW32-ARIN
   Free time?  There's no such thing.  It just comes in varying prices...



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200810162248.m9GMmocw007400>