Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754278AbZKCT0W (ORCPT ); Tue, 3 Nov 2009 14:26:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753324AbZKCT0V (ORCPT ); Tue, 3 Nov 2009 14:26:21 -0500 Received: from d1.icnet.pl ([212.160.220.21]:47188 "EHLO d1.icnet.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753164AbZKCT0V (ORCPT ); Tue, 3 Nov 2009 14:26:21 -0500 From: Janusz Krzysztofik Organization: Tele-Info-System, Poznan, PL To: linux-omap@vger.kernel.org Subject: [RFC] [PATCH v2] OMAP: DMA: Fix omapfb/lcdc on Amstrad Delta broken when PM set Date: Tue, 3 Nov 2009 20:24:38 +0100 User-Agent: KMail/1.9.10 Cc: Tony Lindgren , linux-fbdev-devel@lists.sourceforge.net, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200911032024.47741.jkrzyszt@tis.icnet.pl> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-SA-Exim-Scanned: No (on d1.icnet); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2187 Lines: 61 With CONFIG_PM=y, the omapfb/lcdc device on Amstrad Delta, after initially starting correctly, breaks with the following error messages: omapfb omapfb: resetting (status 0xffffff96,reset count 1) ... omapfb omapfb: resetting (status 0xffffff96,reset count 100) omapfb omapfb: too many reset attempts, giving up. Looking closer at this I have found that it had been broken almost 2 years ago with commit 2418996e3b100114edb2ae110d5d4acb928909d2, PM fixes for OMAP1. The definite reason for broken omapfb/lcdc behavoiur in PM mode appeared to be ARM_IDLECT1:IDLIF_ARM (bit 6) put into idle regardless of LCD DMA possibly running. The bit were set based on return value of the omap_dma_running() function that did not check for dedicated LCD DMA channel status. The patch below fixes this. Created and tested against linux-2.6.32-rc5 Signed-off-by: Janusz Krzysztofik --- Hi, If there are still no comments, especially on the bug possible impact on other OMAP1510 boards (or even OMAP1610 with internal LCD controller), then Tony, please apply it as is. Until it is accepted, I am stuck with new ams_delta_defconfig. Thanks, Janusz --- linux-2.6.32-rc5/arch/arm/plat-omap/dma.c.orig 2009-10-16 02:41:50.000000000 +0200 +++ linux-2.6.32-rc5/arch/arm/plat-omap/dma.c 2009-11-03 20:15:35.000000000 +0100 @@ -30,6 +30,7 @@ #include #include +#include #include #include #include @@ -1110,6 +1111,14 @@ int omap_dma_running(void) { int lch; + /* + * On Amstrad Delta, the OMAP internal LCD controller will start the + * transfer when it gets enabled, so assume DMA running if LCD enabled. + */ + if (machine_is_ams_delta()) + if (omap_readw(0xfffec000 + 0x00) & (1 << 0)) + return 1; + /* Check if LCD DMA is running */ if (cpu_is_omap16xx()) if (omap_readw(OMAP1610_DMA_LCD_CCR) & OMAP_DMA_CCR_EN) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/