From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Alex Deucher" Subject: Re: radeonfb monid i2c bus Date: Mon, 9 Jun 2008 09:02:07 -0400 Message-ID: References: <20080606120151.7976df45@hyperion.delvare> <1212760218.12464.33.camel@pasglop> <20080608162023.431083c7@hyperion.delvare> <20080609091414.2502c49d@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1K5h0j-0002U1-Bd for linux-fbdev-devel@lists.sourceforge.net; Mon, 09 Jun 2008 06:02:10 -0700 Received: from rv-out-0708.google.com ([209.85.198.250]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1K5h0h-0001HD-N3 for linux-fbdev-devel@lists.sourceforge.net; Mon, 09 Jun 2008 06:02:09 -0700 Received: by rv-out-0708.google.com with SMTP id f25so1857557rvb.22 for ; Mon, 09 Jun 2008 06:02:07 -0700 (PDT) In-Reply-To: <20080609091414.2502c49d@hyperion.delvare> Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: Jean Delvare Cc: benh@kernel.crashing.org, linux-fbdev-devel@lists.sourceforge.net On Mon, Jun 9, 2008 at 3:14 AM, Jean Delvare wrote: > Hi Alex, > > Thanks for your answers. > > On Mon, 9 Jun 2008 01:15:00 -0400, Alex Deucher wrote: >> On Sun, Jun 8, 2008 at 10:20 AM, Jean Delvare wrote: >> > But apparently not all chips have the "monid" bus? Or is it a card >> > property, and other cards using the same Radeon 9200 might have it >> > while mine doesn't? I wouldn't care about an empty i2c bus, but a >> > broken bus as I get now affects the whole i2c subsystem and its users >> > in unpleasant ways. That's why I am wondering if there's a way to avoid >> > it. >> >> They are just gpio pads. All the cards supported by radeonfb have >> then, but only certain ones are wired up as per the bios connector >> tables on x86 cards. Mac cards and we currently hard code them based >> on lots of investigation. I suppose, ideally, you check the connector >> tables and some of the other bios tables (powerplay, external tmds, >> ext dac, multimedia. etc.) and only init the buses you have a >> particular card. > > That would indeed make sense. If these are GPIOs, do we even have any > guarantee that they aren't used for other purposes when not used for > I2C? I've always considered the monid I2C bus on my adapters to be > non-existent (i2c-algo-bit can't control the lines) and that's the > reason why I wanted it to not be created, but maybe the GPIO lines are > actually used for something different and creating the non-existent I2C > bus could break that? In theory they could be used for other things, but I'm pretty sure this set (monid, dvi, vga, crt2) is only used for i2c. > > So if it is possible to create the I2C buses (by default, at least) > only when the BIOS connector tables say they are present, I'm in favor > of doing that. That would be ideal, unfortunately, I don't have the time to implement anything like that for radonhd. For anyone interested, the code in the Xorg radeon driver would be a good guide. The drm modesetting work should also alleviate this, once it's done for radeon hw. Alex ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php