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
next 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
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