From owner-freebsd-current@FreeBSD.ORG Wed Jun 25 22:42:49 2014 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 153E58BE; Wed, 25 Jun 2014 22:42:49 +0000 (UTC) Received: from mail.ambrisko.com (mail.ambrisko.com [70.91.206.90]) by mx1.freebsd.org (Postfix) with ESMTP id E3B252DDE; Wed, 25 Jun 2014 22:42:48 +0000 (UTC) X-Ambrisko-Me: Yes Received: from server2.ambrisko.com (HELO internal.ambrisko.com) ([192.168.1.2]) by ironport.ambrisko.com with ESMTP; 25 Jun 2014 15:47:28 -0700 Received: from ambrisko.com (localhost [127.0.0.1]) by internal.ambrisko.com (8.14.4/8.14.4) with ESMTP id s5PMgf94004897; Wed, 25 Jun 2014 15:42:41 -0700 (PDT) (envelope-from ambrisko@ambrisko.com) Received: (from ambrisko@localhost) by ambrisko.com (8.14.4/8.14.4/Submit) id s5PMgfh6004896; Wed, 25 Jun 2014 15:42:41 -0700 (PDT) (envelope-from ambrisko) Date: Wed, 25 Jun 2014 15:42:41 -0700 From: Doug Ambrisko To: sbruno@freebsd.org Subject: Re: SMBus controller Message-ID: <20140625224241.GA21170@ambrisko.com> References: <1402772923.1120.13.camel@bruno> <1402785781.1106.5.camel@bruno> <6F35309D-FA6D-4882-99A2-57346DFF16B9@gmail.com> <1402789710.1106.8.camel@bruno> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1402789710.1106.8.camel@bruno> User-Agent: Mutt/1.4.2.3i Cc: freebsd-current , Warner Losh X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Jun 2014 22:42:49 -0000 On Sat, Jun 14, 2014 at 04:48:30PM -0700, Sean Bruno wrote: | On Sat, 2014-06-14 at 17:25 -0600, Warner Losh wrote: | > On Jun 14, 2014, at 4:43 PM, Sean Bruno wrote: | > | > > On Sat, 2014-06-14 at 12:08 -0700, Sean Bruno wrote: | > >> I note that my TLenovo 61 has one of these: | > >> | > >> ichsmb0@pci0:0:31:3: class=0x0c0500 card=0x20a917aa chip=0x283e8086 | > >> rev=0x03 hdr=0x00 | > >> vendor = 'Intel Corporation' | > >> device = '82801H (ICH8 Family) SMBus Controller' | > >> class = serial bus | > >> subclass = SMBus | > >> | > >> | > > | > > So, there's something broken in the initialization of the driver and the | > > driver dependencies here. | > > | > > If I load "smb.ko" by itself, no other modules are loaded (ichsmb, | > > smbus). Should it? | > | > I don't think so. If I kldload pci, would you expect most of the | > drivers in the system to be loaded? | | Heck if I know. :-) | | I would suspect that of the three, ichsmb, smbus or smb, one of these | should cause the other two to be loaded. This is not the case. ... catching up on email I wouldn't since these act at various levels. ichsmb is the HW interface of which there are different HW interfaces. Then you want the generic stack on that. You might want a user land interface. There are kernel consumers like IPMI SSIF and other things that have been done at companies. So wouldn't expect loading smb to load a i2c printer port bit banger driver of which is wrong for that HW. One word of warning is that it appears ACPI has methods to talk to the i2c bus. I've been concerned that there could be fights between ACPI accessing stuff and FreeBSD native drivers. On the HW that I have used this stuff, it wasn't a problem. I'd be a little concerned on a laptop since a lot of things can be tied to a i2c bus that ACPI wants to talk to. On a server/desktop I haven't run into that problem. I've noticed there seem to be i2c buses for displays which seems to be separate. I've made i2c interface to machines via PCI slots or soldered wires onto DIMMs. Some motherboard have i2c headers. It's easily hackable to add widgets to HW that way since there are so many i2c widgets out there. Doug A.