From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752896Ab2GRJxB (ORCPT ); Wed, 18 Jul 2012 05:53:01 -0400 Received: from protonic.xs4all.nl ([213.84.116.84]:18725 "EHLO protonic.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507Ab2GRJww (ORCPT ); Wed, 18 Jul 2012 05:52:52 -0400 X-Greylist: delayed 1372 seconds by postgrey-1.27 at vger.kernel.org; Wed, 18 Jul 2012 05:52:52 EDT Message-ID: <50068216.9020605@protonic.nl> Date: Wed, 18 Jul 2012 11:29:58 +0200 From: Robin van der Gracht User-Agent: Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: =?UTF-8?B?TG90aGFyIFdhw59tYW5u?= Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [BUGFIX] video/mxsfb: fix crash when unblanking the display References: <1323174425-24038-1-git-send-email-LW@KARO-electronics.de> <20209.35406.958883.977664@ipc1.ka-ro> In-Reply-To: <20209.35406.958883.977664@ipc1.ka-ro> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lothar, > Hi, > > Lothar Waßmann writes: >> The VDCTRL4 register does not provide the MXS SET/CLR/TOGGLE feature. >> The write in mxsfb_disable_controller() sets the data_cnt for the LCD >> DMA to 0 which obviously means the max. count for the LCD DMA and >> leads to overwriting arbitrary memory when the display is unblanked. >> >> Signed-off-by: Lothar Waßmann >> --- >> drivers/video/mxsfb.c | 3 ++- >> 1 files changed, 2 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c >> index d837d63..03cb95a 100644 >> --- a/drivers/video/mxsfb.c >> +++ b/drivers/video/mxsfb.c >> @@ -366,7 +366,8 @@ static void mxsfb_disable_controller(struct fb_info *fb_info) >> loop--; >> } >> >> - writel(VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4 + REG_CLR); >> + reg = readl(host->base + LCDC_VDCTRL4); >> + writel(reg& ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4); >> >> clk_disable(host->clk); >> >> -- >> 1.5.6.5 >> > Ping. Any comments on this? > > > Lothar Waßmann I've encountered this problem to, and i can confirm your patch fixed it. The VDCTRL4 register has no CLR feature. Regards, -- Robin van der Gracht Protonic Holland. tel.: +31 (0) 229 212928 fax.: +31 (0) 229 210930 Factorij 36 / 1689 AL Zwaag