From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>,
Thor Thayer <thor.thayer@linux.intel.com>,
Wolfram Sang <wsa@kernel.org>, Sasha Levin <sashal@kernel.org>,
linux-i2c@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 03/13] i2c: altera: Fix race between xfer_msg and isr thread
Date: Thu, 28 May 2020 07:57:34 -0400 [thread overview]
Message-ID: <20200528115744.1406533-3-sashal@kernel.org> (raw)
In-Reply-To: <20200528115744.1406533-1-sashal@kernel.org>
From: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
[ Upstream commit 5d4c7977499a736f3f80826bdc9744344ad55589 ]
Use a mutex to protect access to idev->msg_len, idev->buf, etc. which
are modified by both altr_i2c_xfer_msg() and altr_i2c_isr().
This is the minimal fix for easy backporting. A cleanup to remove the
spinlock will be added later.
Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Acked-by: Thor Thayer <thor.thayer@linux.intel.com>
[wsa: updated commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/i2c/busses/i2c-altera.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c
index 8915ee30a5b4..1d59eede537b 100644
--- a/drivers/i2c/busses/i2c-altera.c
+++ b/drivers/i2c/busses/i2c-altera.c
@@ -81,6 +81,7 @@
* @isr_mask: cached copy of local ISR enables.
* @isr_status: cached copy of local ISR status.
* @lock: spinlock for IRQ synchronization.
+ * @isr_mutex: mutex for IRQ thread.
*/
struct altr_i2c_dev {
void __iomem *base;
@@ -97,6 +98,7 @@ struct altr_i2c_dev {
u32 isr_mask;
u32 isr_status;
spinlock_t lock; /* IRQ synchronization */
+ struct mutex isr_mutex;
};
static void
@@ -256,10 +258,11 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev)
struct altr_i2c_dev *idev = _dev;
u32 status = idev->isr_status;
+ mutex_lock(&idev->isr_mutex);
if (!idev->msg) {
dev_warn(idev->dev, "unexpected interrupt\n");
altr_i2c_int_clear(idev, ALTR_I2C_ALL_IRQ);
- return IRQ_HANDLED;
+ goto out;
}
read = (idev->msg->flags & I2C_M_RD) != 0;
@@ -312,6 +315,8 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev)
complete(&idev->msg_complete);
dev_dbg(idev->dev, "Message Complete\n");
}
+out:
+ mutex_unlock(&idev->isr_mutex);
return IRQ_HANDLED;
}
@@ -323,6 +328,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
u32 value;
u8 addr = i2c_8bit_addr_from_msg(msg);
+ mutex_lock(&idev->isr_mutex);
idev->msg = msg;
idev->msg_len = msg->len;
idev->buf = msg->buf;
@@ -347,6 +353,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
altr_i2c_int_enable(idev, imask, true);
altr_i2c_fill_tx_fifo(idev);
}
+ mutex_unlock(&idev->isr_mutex);
time_left = wait_for_completion_timeout(&idev->msg_complete,
ALTR_I2C_XFER_TIMEOUT);
@@ -420,6 +427,7 @@ static int altr_i2c_probe(struct platform_device *pdev)
idev->dev = &pdev->dev;
init_completion(&idev->msg_complete);
spin_lock_init(&idev->lock);
+ mutex_init(&idev->isr_mutex);
ret = device_property_read_u32(idev->dev, "fifo-size",
&idev->fifo_size);
--
2.25.1
next prev parent reply other threads:[~2020-05-28 12:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 11:57 [PATCH AUTOSEL 4.14 01/13] ARC: Fix ICCM & DCCM runtime size checks Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 02/13] ARC: [plat-eznps]: Restrict to CONFIG_ISA_ARCOMPACT Sasha Levin
2020-05-28 11:57 ` Sasha Levin [this message]
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 04/13] net sched: fix reporting the first-time use timestamp Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 05/13] x86/mmiotrace: Use cpumask_available() for cpumask_var_t variables Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 06/13] net: bmac: Fix read of MAC address from ROM Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 07/13] r8152: support additional Microsoft Surface Ethernet Adapter variant Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 08/13] net/ethernet/freescale: rework quiesce/activate for ucc_geth Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 09/13] net: ethernet: stmmac: Enable interface clocks on probe for IPQ806x Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 10/13] net: sun: fix missing release regions in cas_init_one() Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 11/13] net/mlx5: Add command entry handling completion Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 12/13] net/mlx4_core: fix a memory leak bug Sasha Levin
2020-05-28 11:57 ` [PATCH AUTOSEL 4.14 13/13] net: smsc911x: Fix runtime PM imbalance on error Sasha Levin
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