From patchwork Mon Aug 15 18:49:32 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 1068782 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7FIouOs023030 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 15 Aug 2011 18:51:18 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qt2Ex-0007ld-6w; Mon, 15 Aug 2011 18:50:23 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Qt2Ew-0007sW-NN; Mon, 15 Aug 2011 18:50:22 +0000 Received: from smtp-out.google.com ([216.239.44.51]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qt2En-0007s6-Ju for linux-arm-kernel@lists.infradead.org; Mon, 15 Aug 2011 18:50:20 +0000 Received: from wpaz24.hot.corp.google.com (wpaz24.hot.corp.google.com [172.24.198.88]) by smtp-out.google.com with ESMTP id p7FInwGO016698; Mon, 15 Aug 2011 11:49:58 -0700 Received: from peppermint.mtv.corp.google.com (peppermint.mtv.corp.google.com [172.22.73.61]) by wpaz24.hot.corp.google.com with ESMTP id p7FInt0X011107; Mon, 15 Aug 2011 11:49:55 -0700 Received: by peppermint.mtv.corp.google.com (Postfix, from userid 121310) id 6D15B19AA0E; Mon, 15 Aug 2011 11:49:55 -0700 (PDT) From: Doug Anderson To: Ben Dooks , Stephen Warren , Vincent Palatin , Rhyland Klein Subject: [PATCH] i2c: tegra: Check for overflow errors with BUG_ON. Date: Mon, 15 Aug 2011 11:49:32 -0700 Message-Id: <1313434172-18319-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.7.3.1 X-System-Of-Record: true X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110815_145013_975295_43A96B1A X-CRM114-Status: GOOD ( 12.63 ) X-Spam-Score: -3.3 (---) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-3.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [216.239.44.51 listed in list.dnswl.org] -1.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: Lucas De Marchi , Doug Anderson , linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, Rakesh Iyer , linux-i2c@vger.kernel.org, Jean Delvare , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Mon, 15 Aug 2011 18:51:18 +0000 (UTC) This change doesn't fix any known problems but turns on the overflow detection feature of the i2c controller in the hopes of flushing out any current (or future) bugs in the i2c driver. Inspired by a change on nvidia's git server: http://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=commit;h=266d1b7397284505e55d06254b497cb32be07b69 Signed-off-by: Doug Anderson --- drivers/i2c/busses/i2c-tegra.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 2440b74..4dbba23 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -367,7 +367,8 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev) static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) { u32 status; - const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST; + const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST | + I2C_INT_TX_FIFO_OVERFLOW; struct tegra_i2c_dev *i2c_dev = dev_id; status = i2c_readl(i2c_dev, I2C_INT_STATUS); @@ -389,6 +390,9 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) } if (unlikely(status & status_err)) { + /* Don't pass this back--it can only happen due to a bug. */ + BUG_ON(status & I2C_INT_TX_FIFO_OVERFLOW); + if (status & I2C_INT_NO_ACK) i2c_dev->msg_err |= I2C_ERR_NO_ACK; if (status & I2C_INT_ARBITRATION_LOST) @@ -423,7 +427,7 @@ err: /* An error occurred, mask all interrupts */ tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST | I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ | - I2C_INT_RX_FIFO_DATA_REQ); + I2C_INT_RX_FIFO_DATA_REQ | I2C_INT_TX_FIFO_OVERFLOW); i2c_writel(i2c_dev, status, I2C_INT_STATUS); if (i2c_dev->is_dvc) dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS); @@ -473,7 +477,8 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, if (!(msg->flags & I2C_M_RD)) tegra_i2c_fill_tx_fifo(i2c_dev); - int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST; + int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST | + I2C_INT_TX_FIFO_OVERFLOW; if (msg->flags & I2C_M_RD) int_mask |= I2C_INT_RX_FIFO_DATA_REQ; else if (i2c_dev->msg_buf_remaining)