All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marek Vasut <marex@denx.de>
To: linux-i2c@vger.kernel.org
Cc: Marek Vasut <marex@denx.de>,
	Michal Simek <michal.simek@xilinx.com>,
	Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>,
	Wolfram Sang <wsa@kernel.org>
Subject: [PATCH 1/5] i2c: xiic: Fix broken locking on tx_msg
Date: Sat, 13 Jun 2020 17:07:47 +0200	[thread overview]
Message-ID: <20200613150751.114595-1-marex@denx.de> (raw)

The tx_msg is set from multiple places, sometimes without locking,
which fall apart on any SMP system. Only ever access tx_msg inside
the driver mutex.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Cc: Wolfram Sang <wsa@kernel.org>
---
 drivers/i2c/busses/i2c-xiic.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index 90c1c362394d0..0777e577720db 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -168,7 +168,7 @@ struct xiic_i2c {
 #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos)
 #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos)
 
-static int xiic_start_xfer(struct xiic_i2c *i2c);
+static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num);
 static void __xiic_start_xfer(struct xiic_i2c *i2c);
 
 /*
@@ -673,15 +673,24 @@ static void __xiic_start_xfer(struct xiic_i2c *i2c)
 
 }
 
-static int xiic_start_xfer(struct xiic_i2c *i2c)
+static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num)
 {
 	int ret;
+
 	mutex_lock(&i2c->lock);
 
+	ret = xiic_busy(i2c);
+	if (ret)
+		goto out;
+
+	i2c->tx_msg = msgs;
+	i2c->nmsgs = num;
+
 	ret = xiic_reinit(i2c);
 	if (!ret)
 		__xiic_start_xfer(i2c);
 
+out:
 	mutex_unlock(&i2c->lock);
 
 	return ret;
@@ -699,14 +708,7 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	if (err < 0)
 		return err;
 
-	err = xiic_busy(i2c);
-	if (err)
-		goto out;
-
-	i2c->tx_msg = msgs;
-	i2c->nmsgs = num;
-
-	err = xiic_start_xfer(i2c);
+	err = xiic_start_xfer(i2c, msgs, num);
 	if (err < 0) {
 		dev_err(adap->dev.parent, "Error xiic_start_xfer\n");
 		goto out;
@@ -714,9 +716,11 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 
 	if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
 		(i2c->state == STATE_DONE), HZ)) {
+		mutex_lock(&i2c->lock);
 		err = (i2c->state == STATE_DONE) ? num : -EIO;
 		goto out;
 	} else {
+		mutex_lock(&i2c->lock);
 		i2c->tx_msg = NULL;
 		i2c->rx_msg = NULL;
 		i2c->nmsgs = 0;
@@ -724,6 +728,7 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 		goto out;
 	}
 out:
+	mutex_unlock(&i2c->lock);
 	pm_runtime_mark_last_busy(i2c->dev);
 	pm_runtime_put_autosuspend(i2c->dev);
 	return err;
-- 
2.26.2


             reply	other threads:[~2020-06-13 15:08 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-13 15:07 Marek Vasut [this message]
2020-06-13 15:07 ` [PATCH 2/5] i2c: xiic: Drop broken interrupt handler Marek Vasut
2020-06-17 12:25   ` Shubhrajyoti Datta
2020-06-17 12:31     ` Marek Vasut
2020-06-26 12:13   ` Raviteja Narayanam
2020-06-28 23:41     ` Marek Vasut
2020-06-29 12:52       ` Raviteja Narayanam
2020-06-29 21:50         ` Marek Vasut
2020-07-08 15:23           ` Raviteja Narayanam
2020-08-19 17:42             ` Marek Vasut
2020-08-24  8:27               ` Raviteja Narayanam
2020-08-24 11:58                 ` Marek Vasut
2020-08-25  9:44                   ` Raviteja Narayanam
2020-08-25 20:50                     ` Marek Vasut
2020-09-07  8:51                       ` Raviteja Narayanam
2020-09-08 14:04                         ` Marek Vasut
2020-09-11 10:28                           ` Michal Simek
2020-06-13 15:07 ` [PATCH 3/5] i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in xiic_process() Marek Vasut
2020-06-26 12:13   ` Raviteja Narayanam
2020-07-08 15:23     ` Raviteja Narayanam
2020-06-13 15:07 ` [PATCH 4/5] i2c: xiic: Switch from waitqueue to completion Marek Vasut
2020-06-26 12:13   ` Raviteja Narayanam
2020-06-28 23:41     ` Marek Vasut
2020-06-29 12:53       ` Raviteja Narayanam
2020-06-29 21:52         ` Marek Vasut
2020-06-13 15:07 ` [PATCH 5/5] i2c: xiic: Only ever transfer single message Marek Vasut
2020-06-13 19:33   ` Wolfram Sang
2020-06-13 19:37     ` Marek Vasut
2020-06-13 19:42       ` Wolfram Sang
2020-07-13  8:37         ` Michal Simek
2020-06-26 12:14   ` Raviteja Narayanam
2020-06-26 12:11 ` [PATCH 1/5] i2c: xiic: Fix broken locking on tx_msg Raviteja Narayanam
2020-06-28 23:18   ` Marek Vasut
2020-06-29 12:52     ` Raviteja Narayanam
2020-07-08 15:23       ` Raviteja Narayanam

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200613150751.114595-1-marex@denx.de \
    --to=marex@denx.de \
    --cc=linux-i2c@vger.kernel.org \
    --cc=michal.simek@xilinx.com \
    --cc=shubhrajyoti.datta@xilinx.com \
    --cc=wsa@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.