From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758159Ab0G2Ucc (ORCPT ); Thu, 29 Jul 2010 16:32:32 -0400 Received: from mail1-out1.atlantis.sk ([80.94.52.55]:38102 "EHLO mail.atlantis.sk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750767Ab0G2Uca (ORCPT ); Thu, 29 Jul 2010 16:32:30 -0400 To: "Russell King - ARM Linux" Subject: [PATCH v2] cyber2000fb: fix machine hang on module load Cc: linux-fbdev@vger.kernel.org, Kernel development list Content-Disposition: inline From: Ondrej Zary Date: Thu, 29 Jul 2010 22:32:20 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201007292232.22418.linux@rainbow-software.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I was testing two CyberPro 2000 based PCI cards on x86 and the machine always hanged completely when the cyber2000fb module was loaded. It seems that the card hangs when some registers are accessed too quickly after writing RAMDAC control register. With this patch, both card work. Add delay after RAMDAC control register write to prevent hangs on module load. Signed-off-by: Ondrej Zary --- linux-2.6.35-rc2-orig/drivers/video/cyber2000fb.c 2010-06-06 05:43:24.000000000 +0200 +++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c 2010-07-27 23:12:37.000000000 +0200 @@ -436,6 +436,8 @@ static void cyber2000fb_write_ramdac_ctr cyber2000fb_writeb(i | 4, 0x3cf, cfb); cyber2000fb_writeb(val, 0x3c6, cfb); cyber2000fb_writeb(i, 0x3cf, cfb); + /* prevent card lock-up observed on x86 with CyberPro 2000 */ + cyber2000fb_readb(0x3cf, cfb); } static void cyber2000fb_set_timing(struct cfb_info *cfb, struct par_info *hw) -- Ondrej Zary