diff options
| author |   Wolfram Sang <wsa+renesas@sang-engineering.com> | 2019-08-08 21:54:17 +0200 |
|---|---|---|
| committer |   Wolfram Sang <wsa@the-dreams.de> | 2019-08-14 14:49:43 +0200 |
| commit | d7437fc0d8291181debe032671a289b6bd93f46f (patch) | |
| tree | 7eabc9f12af39ab71bee73ab3927e84219b5ef94 /drivers/i2c | |
| parent | i2c: rcar: avoid race when unregistering slave client (diff) | |
| download | linux-dev-d7437fc0d8291181debe032671a289b6bd93f46f.tar.xz linux-dev-d7437fc0d8291181debe032671a289b6bd93f46f.zip | |
i2c: emev2: avoid race when unregistering slave client
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>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-emev2.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-emev2.c b/drivers/i2c/busses/i2c-emev2.c index 35b302d983e0..959d4912ec0d 100644 --- a/drivers/i2c/busses/i2c-emev2.c +++ b/drivers/i2c/busses/i2c-emev2.c @@ -69,6 +69,7 @@ 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) @@ -339,6 +340,12 @@ 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; @@ -355,7 +362,7 @@ 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) @@ -390,8 +397,8 @@ 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; @@ -401,7 +408,8 @@ 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; |