From patchwork Thu Sep 3 20:20:09 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 7119211 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id F06F49F36E for ; Thu, 3 Sep 2015 20:23:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0807920713 for ; Thu, 3 Sep 2015 20:23:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04A5920708 for ; Thu, 3 Sep 2015 20:23:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753985AbbICUXT (ORCPT ); Thu, 3 Sep 2015 16:23:19 -0400 Received: from sauhun.de ([89.238.76.85]:48412 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753827AbbICUXT (ORCPT ); Thu, 3 Sep 2015 16:23:19 -0400 Received: from p4fe253c4.dip0.t-ipconnect.de ([79.226.83.196]:39706 helo=localhost) by pokefinder.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1ZXb2S-0003Qy-QH; Thu, 03 Sep 2015 22:23:17 +0200 From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-sh@vger.kernel.org, Magnus Damm , Simon Horman , Laurent Pinchart , Geert Uytterhoeven , Wolfram Sang , Kuninori Morimoto , Yoshihiro Kaneko , Sergei Shtylyov Subject: [PATCH 5/9] i2c: rcar: init new messages in irq Date: Thu, 3 Sep 2015 22:20:09 +0200 Message-Id: <1441311613-2681-6-git-send-email-wsa@the-dreams.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1441311613-2681-1-git-send-email-wsa@the-dreams.de> References: <1441311613-2681-1-git-send-email-wsa@the-dreams.de> Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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: Wolfram Sang Setting up new messages was done in process context while handling a message was in interrupt context. Because of the HW design, this IP core is sensitive to timing, so the context switches were too expensive. Move this setup to interrupt context as well. In my test setup, this fixed the occasional 'data byte sent twice' issue which a number of people have seen. It also fixes to send REP_START after a read message which was wrongly send as a STOP + START sequence before. Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-rcar.c | 74 +++++++++++++++++++++---------------------- 1 file changed, 37 insertions(+), 37 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 6e459a338ccc75..36c79301044b71 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -266,6 +266,13 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND); } +static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv) +{ + priv->msg++; + priv->msgs_left--; + rcar_i2c_prepare_msg(priv); +} + /* * interrupt functions */ @@ -308,21 +315,17 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * [ICRXTX] -> [SHIFT] -> [I2C bus] */ - if (priv->flags & ID_LAST_MSG) + if (priv->flags & ID_LAST_MSG) { /* * If current msg is the _LAST_ msg, * prepare stop condition here. * ID_DONE will be set on STOP irq. */ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); - else - /* - * If current msg is _NOT_ last msg, - * it doesn't call stop phase. - * thus, there is no STOP irq. - * return ID_DONE here. - */ - return ID_DONE; + } else { + rcar_i2c_next_msg(priv); + return 0; + } } rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND); @@ -366,7 +369,10 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) else rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); - rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); + if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG)) + rcar_i2c_next_msg(priv); + else + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); return 0; } @@ -461,6 +467,7 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) /* Stop */ if (msr & MST) { + priv->msgs_left--; /* The last message also made it */ rcar_i2c_flags_set(priv, ID_DONE); goto out; } @@ -500,35 +507,28 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, /* This HW can't send STOP after address phase */ if (msgs[i].len == 0) { ret = -EOPNOTSUPP; - break; - } - - /* init each data */ - priv->msg = &msgs[i]; - priv->msgs_left = num - i; - - rcar_i2c_prepare_msg(priv); - - time_left = wait_event_timeout(priv->wait, - rcar_i2c_flags_has(priv, ID_DONE), - adap->timeout); - if (!time_left) { - rcar_i2c_init(priv); - ret = -ETIMEDOUT; - break; - } - - if (rcar_i2c_flags_has(priv, ID_NACK)) { - ret = -ENXIO; - break; - } - - if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { - ret = -EAGAIN; - break; + goto out; } + } - ret = i + 1; /* The number of transfer */ + /* init data */ + priv->msg = msgs; + priv->msgs_left = num; + + rcar_i2c_prepare_msg(priv); + + time_left = wait_event_timeout(priv->wait, + rcar_i2c_flags_has(priv, ID_DONE), + num * adap->timeout); + if (!time_left) { + rcar_i2c_init(priv); + ret = -ETIMEDOUT; + } else if (rcar_i2c_flags_has(priv, ID_NACK)) { + ret = -ENXIO; + } else if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { + ret = -EAGAIN; + } else { + ret = num - priv->msgs_left; /* The number of transfer */ } out: pm_runtime_put(dev);