[PATCH 1/2] i2c: designware: Avoid taking clk_prepare mutex in PM callbacks

[Jisheng Zhang <jszhang@kernel.org>]

This is unsafe, as the runtime PM callbacks are called from the PM
workqueue, so this may deadlock when handling an i2c attached clock,
which may already hold the clk_prepare mutex from another context.

Fixes: 1fc2fe204cb9 ("i2c: designware: Add runtime PM hooks")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 drivers/i2c/busses/i2c-designware-common.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 5b1e8f74c4ac..b4e38bc0f876 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -776,7 +776,8 @@ static int i2c_dw_runtime_suspend(struct device *device)
 		return 0;
 
 	i2c_dw_disable(dev);
-	i2c_dw_prepare_clk(dev, false);
+	clk_disable(dev->clk);
+	clk_disable(dev->pclk);
 
 	return 0;
 }
@@ -794,8 +795,10 @@ static int i2c_dw_runtime_resume(struct device *device)
 {
 	struct dw_i2c_dev *dev = dev_get_drvdata(device);
 
-	if (!dev->shared_with_punit)
-		i2c_dw_prepare_clk(dev, true);
+	if (!dev->shared_with_punit) {
+		clk_enable(dev->pclk);
+		clk_enable(dev->clk);
+	}
 
 	dev->init(dev);
 
-- 
2.50.1