From owner-freebsd-hackers Mon Jul 3 19:10: 5 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from mass.osd.bsdi.com (mg136-135.ricochet.net [204.179.136.135]) by hub.freebsd.org (Postfix) with ESMTP id 669B637C294 for ; Mon, 3 Jul 2000 19:05:00 -0700 (PDT) (envelope-from msmith@mass.osd.bsdi.com) Received: from mass.osd.bsdi.com (localhost [127.0.0.1]) by mass.osd.bsdi.com (8.9.3/8.9.3) with ESMTP id TAA00657; Mon, 3 Jul 2000 19:10:01 -0700 (PDT) (envelope-from msmith@mass.osd.bsdi.com) Message-Id: <200007040210.TAA00657@mass.osd.bsdi.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Lyndon Nerenberg Cc: freebsd-hackers@freebsd.org Subject: Re: Concurrent access to SMbus In-reply-to: Your message of "Mon, 05 Jun 2000 14:47:04 MDT." <200006052047.e55Kl5X51895@orthanc.ab.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 03 Jul 2000 19:09:58 -0700 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I notice that the /dev/smbX devices are exclusive access. This makes > it impossible to run two (or more) programs concurrently that want > to talk to SMbus devices (in my case, healthd and lmmon, both of which > want to open /dev/smb0 to access the LM78). > > Is this an SMbus restriction, or an artifact of the smb driver? I did a > very quick scan through /sys/dev/smbus/* and nothing jumped out to > indicate why it needs to be exclusive access. Transactions on the bus should be locked, ie. only one client talking at a time, but it should probably be feasible to allow more than one opener. The SMBus code is dearly in need of a maintainer. 8( -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message