From patchwork Thu Feb 16 14:47:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 141613 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from merlin.infradead.org (unknown [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 40296B6F62 for ; Fri, 17 Feb 2012 01:51:11 +1100 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Ry2dD-0002va-2R; Thu, 16 Feb 2012 14:48:23 +0000 Received: from bombadil.infradead.org ([2001:4830:2446:ff00:4687:fcff:fea6:5117]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Ry2d5-0002s3-TG for linux-arm-kernel@merlin.infradead.org; Thu, 16 Feb 2012 14:48:16 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Ry2cz-00025j-6b for linux-arm-kernel@lists.infradead.org; Thu, 16 Feb 2012 14:48:14 +0000 Received: from katana.hi.pengutronix.de ([2001:6f8:1178:2:221:70ff:fe71:1890] helo=pengutronix.de) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1Ry2ch-0000vy-LZ; Thu, 16 Feb 2012 15:47:51 +0100 From: Wolfram Sang To: linux-i2c@vger.kernel.org Subject: [PATCH RESEND] i2c: mxs: only flag completion when queue is completely done Date: Thu, 16 Feb 2012 15:47:44 +0100 Message-Id: <1329403664-17936-1-git-send-email-w.sang@pengutronix.de> X-Mailer: git-send-email 1.7.9 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:6f8:1178:2:221:70ff:fe71:1890 X-SA-Exim-Mail-From: w.sang@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20120216_094809_466058_3E690C22 X-CRM114-Status: GOOD ( 14.08 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on bombadil.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Wolfram Sang , Marek Vasut , linux-arm-kernel@lists.infradead.org, Shawn Guo , Ben Dooks , =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org The hardware generates an interrupt for every completed command in the queue while the code assumed that it will only generate one interrupt when the queue is empty. So, explicitly check if the queue is really empty. This patch fixed problems which occurred due to high traffic on the bus. While we are here, move the completion-initialization after the parameter error checking. Signed-off-by: Wolfram Sang Cc: Shawn Guo Cc: Marek Vasut Cc: Lothar Waßmann Cc: Ben Dooks --- Ben, will you send this to Linus? Should get a stable tag, too, IMO. drivers/i2c/busses/i2c-mxs.c | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 7e78f7c..3d471d5 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -72,6 +72,7 @@ #define MXS_I2C_QUEUESTAT (0x70) #define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY 0x00002000 +#define MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK 0x0000001F #define MXS_I2C_QUEUECMD (0x80) @@ -219,14 +220,14 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int ret; int flags; - init_completion(&i2c->cmd_complete); - dev_dbg(i2c->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", msg->addr, msg->len, msg->flags, stop); if (msg->len == 0) return -EINVAL; + init_completion(&i2c->cmd_complete); + flags = stop ? MXS_I2C_CTRL0_POST_SEND_STOP : 0; if (msg->flags & I2C_M_RD) @@ -286,6 +287,7 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) { struct mxs_i2c_dev *i2c = dev_id; u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK; + bool is_last_cmd; if (!stat) return IRQ_NONE; @@ -300,9 +302,14 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) else i2c->cmd_err = 0; - complete(&i2c->cmd_complete); + is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) & + MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0; + + if (is_last_cmd || i2c->cmd_err) + complete(&i2c->cmd_complete); writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR); + return IRQ_HANDLED; }