From patchwork Mon May 30 14:25:33 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Balaji T K X-Patchwork-Id: 830182 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p4UEODhk018815 for ; Mon, 30 May 2011 14:28:31 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756913Ab1E3O1P (ORCPT ); Mon, 30 May 2011 10:27:15 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:40453 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756238Ab1E3O1N (ORCPT ); Mon, 30 May 2011 10:27:13 -0400 Received: from dbdp20.itg.ti.com ([172.24.170.38]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id p4UER5UU011311 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 30 May 2011 09:27:07 -0500 Received: from dbde70.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id p4UER3T6029695; Mon, 30 May 2011 19:57:05 +0530 (IST) Received: from dbdp31.itg.ti.com (172.24.170.98) by DBDE70.ent.ti.com (172.24.170.148) with Microsoft SMTP Server id 8.3.106.1; Mon, 30 May 2011 19:57:03 +0530 Received: from localhost.localdomain (a0393241pc.india.ti.com [172.24.136.78]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id p4UEQxKB014390; Mon, 30 May 2011 19:57:03 +0530 (IST) From: Balaji T K To: , , CC: , , , Balaji T K Subject: [PATCH 1/2] ARM: OMAP4: MMC: increase delay for pbias Date: Mon, 30 May 2011 19:55:33 +0530 Message-ID: <1306765534-20103-2-git-send-email-balajitk@ti.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1306765534-20103-1-git-send-email-balajitk@ti.com> References: <1306765534-20103-1-git-send-email-balajitk@ti.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 30 May 2011 14:28:31 +0000 (UTC) 4 micro seconds is not enough for PBIAS if MMC regulator is enabled from MMC regulator OFF. Increase the delay for PBIAS to stabilize. Wait for PBIAS and timeout if not. Resolves MMC/SD failure on OMAP4 "Pbias Voltage is not same as LDO" Signed-off-by: Balaji T K --- arch/arm/mach-omap2/hsmmc.c | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c index b2f30be..3f8dc16 100644 --- a/arch/arm/mach-omap2/hsmmc.c +++ b/arch/arm/mach-omap2/hsmmc.c @@ -145,6 +145,7 @@ static void omap4_hsmmc1_after_set_reg(struct device *dev, int slot, int power_on, int vdd) { u32 reg; + unsigned long timeout; if (power_on) { reg = omap4_ctrl_pad_readl(control_pbias_offset); @@ -157,9 +158,15 @@ static void omap4_hsmmc1_after_set_reg(struct device *dev, int slot, OMAP4_MMC1_PWRDNZ_MASK | OMAP4_USBC1_ICUSB_PWRDNZ_MASK); omap4_ctrl_pad_writel(reg, control_pbias_offset); - /* 4 microsec delay for comparator to generate an error*/ - udelay(4); - reg = omap4_ctrl_pad_readl(control_pbias_offset); + + timeout = jiffies + msecs_to_jiffies(5); + do { + reg = omap4_ctrl_pad_readl(control_pbias_offset); + if (!(reg & OMAP4_MMC1_PBIASLITE_VMODE_ERROR_MASK)) + break; + udelay(100); + } while (!time_after(jiffies, timeout)); + if (reg & OMAP4_MMC1_PBIASLITE_VMODE_ERROR_MASK) { pr_err("Pbias Voltage is not same as LDO\n"); /* Caution : On VMODE_ERROR Power Down MMC IO */