[PATCH 4.14 076/189] i2c: sprd: Prevent i2c accesses after suspend is called

Greg Kroah-Hartman
2018-06-18T09:01:13Z

From: Baolin Wang <baolin.wang@linaro.org>

[ Upstream commit da33aa03fa34c918faf2c371ebda0dd961d7ccb2 ]

Add one flag to indicate if the i2c controller has been in suspend state,
which can prevent i2c accesses after i2c controller is suspended following
system suspend.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/i2c/busses/i2c-sprd.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -86,6 +86,7 @@ struct sprd_i2c {
u32 count;
int irq;
int err;
+ bool is_suspended;
};

static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
@@ -283,6 +284,9 @@ static int sprd_i2c_master_xfer(struct i
struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
int im, ret;

+ if (i2c_dev->is_suspended)
+ return -EBUSY;
+
ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0)
return ret;
@@ -586,11 +590,23 @@ static int sprd_i2c_remove(struct platfo

static int __maybe_unused sprd_i2c_suspend_noirq(struct device *pdev)
{
+ struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
+
+ i2c_lock_adapter(&i2c_dev->adap);
+ i2c_dev->is_suspended = true;
+ i2c_unlock_adapter(&i2c_dev->adap);
+
return pm_runtime_force_suspend(pdev);
}

static int __maybe_unused sprd_i2c_resume_noirq(struct device *pdev)
{
+ struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
+
+ i2c_lock_adapter(&i2c_dev->adap);
+ i2c_dev->is_suspended = false;
+ i2c_unlock_adapter(&i2c_dev->adap);
+
return pm_runtime_force_resume(pdev);
}