From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968536AbeE2WZG (ORCPT ); Tue, 29 May 2018 18:25:06 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:44100 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S968507AbeE2WYw (ORCPT ); Tue, 29 May 2018 18:24:52 -0400 From: Eddie James To: linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, wsa@the-dreams.de, robh+dt@kernel.org, benh@kernel.crashing.org, joel@jms.id.au, mark.rutland@arm.com, gregkh@linuxfoundation.org, "Edward A. James" Subject: [PATCH v7 6/7] drivers/i2c: Add I2C master locking to FSI algorithm Date: Tue, 29 May 2018 17:24:24 -0500 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1527632665-25707-1-git-send-email-eajames@linux.vnet.ibm.com> References: <1527632665-25707-1-git-send-email-eajames@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18052922-0020-0000-0000-00000E0A1422 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009097; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000264; SDB=6.01039557; UDB=6.00532065; IPR=6.00818685; MB=3.00021364; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-29 22:24:49 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052922-0021-0000-0000-000061A51D7C Message-Id: <1527632665-25707-7-git-send-email-eajames@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-29_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1805290238 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Edward A. James" Since there are many ports per master, each with it's own adapter and chardev, we need some locking to prevent transfers from changing the master state while other transfers are in progress. Signed-off-by: Edward A. James --- drivers/i2c/busses/i2c-fsi.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 78e3586..f309267 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #define FSI_ENGID_I2C 0x7 @@ -143,6 +144,7 @@ struct fsi_i2c_master { struct fsi_device *fsi; u8 fifo_size; struct list_head ports; + struct mutex lock; }; struct fsi_i2c_port { @@ -585,11 +587,14 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int i, rc; unsigned long start_time; struct fsi_i2c_port *port = adap->algo_data; + struct fsi_i2c_master *master = port->master; struct i2c_msg *msg; + mutex_lock(&master->lock); + rc = fsi_i2c_set_port(port); if (rc) - return rc; + goto unlock; for (i = 0; i < num; ++i) { msg = msgs + i; @@ -597,15 +602,17 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, rc = fsi_i2c_start(port, msg, i == num - 1); if (rc) - return rc; + goto unlock; rc = fsi_i2c_wait(port, msg, adap->timeout - (jiffies - start_time)); if (rc) - return rc; + goto unlock; } - return 0; +unlock: + mutex_unlock(&master->lock); + return rc; } static u32 fsi_i2c_functionality(struct i2c_adapter *adap) @@ -631,6 +638,7 @@ static int fsi_i2c_probe(struct device *dev) if (!i2c) return -ENOMEM; + mutex_init(&i2c->lock); i2c->fsi = to_fsi_dev(dev); INIT_LIST_HEAD(&i2c->ports); -- 1.8.3.1