From patchwork Thu Apr 17 17:59:24 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 4010071 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9E2C79F2BA for ; Thu, 17 Apr 2014 18:00:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C3E2C201BB for ; Thu, 17 Apr 2014 18:00:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0536420117 for ; Thu, 17 Apr 2014 18:00:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752128AbaDQSAX (ORCPT ); Thu, 17 Apr 2014 14:00:23 -0400 Received: from mail-ig0-f202.google.com ([209.85.213.202]:45443 "EHLO mail-ig0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751139AbaDQSAS (ORCPT ); Thu, 17 Apr 2014 14:00:18 -0400 Received: by mail-ig0-f202.google.com with SMTP id uq10so75591igb.3 for ; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=BllE3TrDDCFvli9CAUypqopHlE2rn7s9F2RlfYxsX0E=; b=cljn1G3mEKjL25El4/ZCM4PAFnGln8BnRWA8aRDUeV/dIcDVUW6AF5Gf77SNwrSySm FWIpWabpXS5tt9ax3fnFY4o5r7RAZOmS9ALCFsbCSG9PKsCKIejSkpAG4YvrAoCZa6iq NUXbG+oXKxURQIRB3m+yWQE7DyPBEqmXss9C3R9OZmHLK0MJzUDs2K5V+EWdJui24zKW 3HuANPko0FkW7cKiTjSlI5Ovbcw+IYa1alABrNK+8wRfYiIGwdeuZZpVVv/ZvCWZh3m7 QUNgY8U2itufrv6uX2X1IMfRynjJbfWPRWwp/ubVjSMDdd5j9/3ddqLq8xPTakyZKZcu xR4g== X-Gm-Message-State: ALoCoQnq7iMEEyHSot4ND4oV53utB8kXahnFxB6rxvh6GdMDNb6NivULFdNXdlD4bqhZxHFfYnaWFiLJdPd/NNXMjU25NCcS1YAmMIXgi2VuQP8+ZLGZKqLyZIrUce+P2WmKvZ8mgkpd/E2IRDfEZRFlqMrmYy++45Ypgw3FKqnX3cXrUQLBnPyfbyCkHfjvGOrpGK1i6YI9ZzcurodsnTcJZO6IzcePZg== X-Received: by 10.182.216.200 with SMTP id os8mr8136532obc.0.1397757617710; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) Received: from corp2gmr1-1.hot.corp.google.com (corp2gmr1-1.hot.corp.google.com [172.24.189.92]) by gmr-mx.google.com with ESMTPS id e40si3612311yhf.0.2014.04.17.11.00.17 for (version=TLSv1.1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 17 Apr 2014 11:00:17 -0700 (PDT) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.72.141]) by corp2gmr1-1.hot.corp.google.com (Postfix) with ESMTP id 852B931C2F7; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id 35F2E804B3; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) From: Doug Anderson To: Lee Jones , Stephen Warren , Wolfram Sang Cc: abrestic@chromium.org, dgreid@chromium.org, Olof Johansson , Simon Glass , linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, David Hendricks , Doug Anderson , Samuel Ortiz , linux-kernel@vger.kernel.org Subject: [PATCH 1/7] mfd: cros_ec: spi: calculate delay between transfers correctly Date: Thu, 17 Apr 2014 10:59:24 -0700 Message-Id: <1397757570-19750-2-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.9.1.423.g4596e3a In-Reply-To: <1397757570-19750-1-git-send-email-dianders@chromium.org> References: <1397757570-19750-1-git-send-email-dianders@chromium.org> Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: David Hendricks To avoid spamming the EC we calculate the time between the previous transfer and the current transfer and force a delay if the time delta is too small. However, a small miscalculation causes the delay period to be far too short. Most noticably this impacts commands with a long turnaround time such as EC firmware reads and writes. Signed-off-by: David Hendricks Signed-off-by: Doug Anderson Reviewed-by: Simon Glass --- drivers/mfd/cros_ec_spi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index 84af8d7..c185eb6 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -219,7 +219,7 @@ static int cros_ec_command_spi_xfer(struct cros_ec_device *ec_dev, ktime_get_ts(&ts); delay = timespec_to_ns(&ts) - ec_spi->last_transfer_ns; if (delay < EC_SPI_RECOVERY_TIME_NS) - ndelay(delay); + ndelay(EC_SPI_RECOVERY_TIME_NS - delay); } /* Transmit phase - send our message */