From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: [PATCH] radeonfb: DDC i2c fix Date: Fri, 11 Mar 2005 16:46:10 +1100 Message-ID: <1110519970.5751.17.camel@gaston> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1D9cya-0007Ft-Pw for linux-fbdev-devel@lists.sourceforge.net; Thu, 10 Mar 2005 21:46:20 -0800 Received: from gate.crashing.org ([63.228.1.57]) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1D9cyZ-00054n-4f for linux-fbdev-devel@lists.sourceforge.net; Thu, 10 Mar 2005 21:46:20 -0800 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: Linux Fbdev development list Hi ! The radeonfb code for DDC probing (like it's X.org counterpart) uses to leave the DDC clock & data lines asserted after the probing is complete. This causes problems with some Apple monitors like the new Cinema HD 23", who will turn themselves off when that happens. This fixes it. Signed-off-by: Benjamin Herrenschmidt Index: linux-work/drivers/video/aty/radeon_i2c.c =================================================================== --- linux-work.orig/drivers/video/aty/radeon_i2c.c 2005-01-24 17:09:44.000000000 +1100 +++ linux-work/drivers/video/aty/radeon_i2c.c 2005-03-04 17:26:42.000000000 +1100 @@ -236,6 +236,12 @@ if (edid) break; } + /* Release the DDC lines when done or the Apple Cinema HD display + * will switch off + */ + OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN | VGA_DDC_DATA_OUT_EN)); + (void)INREG(reg); + if (out_edid) *out_edid = edid; if (!edid) { ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click