From patchwork Sat Mar 16 06:16:41 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lokesh Vutla X-Patchwork-Id: 2281611 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 820003FC8F for ; Sat, 16 Mar 2013 06:19:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752726Ab3CPGRB (ORCPT ); Sat, 16 Mar 2013 02:17:01 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:38655 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752685Ab3CPGQ7 (ORCPT ); Sat, 16 Mar 2013 02:16:59 -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 r2G6Gtlc011076; Sat, 16 Mar 2013 01:16:56 -0500 Received: from DBDE71.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id r2G6GtLr014979; Sat, 16 Mar 2013 11:46:55 +0530 (IST) Received: from dbdp33.itg.ti.com (172.24.170.252) by DBDE71.ent.ti.com (172.24.170.149) with Microsoft SMTP Server id 14.1.323.3; Sat, 16 Mar 2013 11:46:54 +0530 Received: from a0131933lt.itg.ti.com (smtpvbd.itg.ti.com [172.24.170.250]) by dbdp33.itg.ti.com (8.13.8/8.13.8) with ESMTP id r2G6Gnm1003136; Sat, 16 Mar 2013 11:46:53 +0530 From: Lokesh Vutla To: CC: , , , , Subject: [PATCH V2 1/8] memory: emif: Fix the lpmode timeout calculation Date: Sat, 16 Mar 2013 11:46:41 +0530 Message-ID: <1363414608-7448-2-git-send-email-lokeshvutla@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1363414608-7448-1-git-send-email-lokeshvutla@ti.com> References: <1363414608-7448-1-git-send-email-lokeshvutla@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 The driver tries to round up the specified timeout cycles to the next power of 2 value. This should be done defore updating timeout variable. Correcting this here. Reported-by: Nishanth Menon Signed-off-by: Lokesh Vutla Acked-by: Santosh Shilimkar --- Changes since V1: Updated Changelog and $subject Added a comment describing timeout calculation. drivers/memory/emif.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c index df08736..508763c 100644 --- a/drivers/memory/emif.c +++ b/drivers/memory/emif.c @@ -728,13 +728,17 @@ static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev) /* Timeout based on DDR frequency */ timeout = freq >= freq_threshold ? timeout_perf : timeout_pwr; - /* The value to be set in register is "log2(timeout) - 3" */ + /* + * The value to be set in register is "log2(timeout) - 3" + * if timeout < 16 load 0 in register + * if timeout is not a power of 2, round to next highest power of 2 + */ if (timeout < 16) { timeout = 0; } else { - timeout = __fls(timeout) - 3; if (timeout & (timeout - 1)) - timeout++; + timeout <<= 1; + timeout = __fls(timeout) - 3; } switch (lpmode) {