From: Wolfram Sang wsa+renesas@sang-engineering.com
[ Upstream commit d7437fc0d8291181debe032671a289b6bd93f46f ]
After we disabled interrupts, there might still be an active one running. Sync before clearing the pointer to the slave device.
Fixes: c31d0a00021d ("i2c: emev2: add slave support") Reported-by: Krzysztof Adamski krzysztof.adamski@nokia.com Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Reviewed-by: Krzysztof Adamski krzysztof.adamski@nokia.com Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-emev2.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-emev2.c b/drivers/i2c/busses/i2c-emev2.c index 96bb4e7490128..0218ba6eb26ab 100644 --- a/drivers/i2c/busses/i2c-emev2.c +++ b/drivers/i2c/busses/i2c-emev2.c @@ -72,6 +72,7 @@ struct em_i2c_device { struct completion msg_done; struct clk *sclk; struct i2c_client *slave; + int irq; };
static inline void em_clear_set_bit(struct em_i2c_device *priv, u8 clear, u8 set, u8 reg) @@ -342,6 +343,12 @@ static int em_i2c_unreg_slave(struct i2c_client *slave)
writeb(0, priv->base + I2C_OFS_SVA0);
+ /* + * Wait for interrupt to finish. New slave irqs cannot happen because we + * cleared the slave address and, thus, only extension codes will be + * detected which do not use the slave ptr. + */ + synchronize_irq(priv->irq); priv->slave = NULL;
return 0; @@ -358,7 +365,7 @@ static int em_i2c_probe(struct platform_device *pdev) { struct em_i2c_device *priv; struct resource *r; - int irq, ret; + int ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -391,8 +398,8 @@ static int em_i2c_probe(struct platform_device *pdev)
em_i2c_reset(&priv->adap);
- irq = platform_get_irq(pdev, 0); - ret = devm_request_irq(&pdev->dev, irq, em_i2c_irq_handler, 0, + priv->irq = platform_get_irq(pdev, 0); + ret = devm_request_irq(&pdev->dev, priv->irq, em_i2c_irq_handler, 0, "em_i2c", priv); if (ret) goto err_clk; @@ -402,7 +409,8 @@ static int em_i2c_probe(struct platform_device *pdev) if (ret) goto err_clk;
- dev_info(&pdev->dev, "Added i2c controller %d, irq %d\n", priv->adap.nr, irq); + dev_info(&pdev->dev, "Added i2c controller %d, irq %d\n", priv->adap.nr, + priv->irq);
return 0;