diff options
| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2019-08-08 21:54:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-06 10:19:42 +0200 |
| commit | 1fe671b62a33ada57a7c586fd9e0184e4d6fc443 (patch) | |
| tree | a470e45ccf4e955d43cc0dd41e86f8adc1acad83 /drivers/i2c/busses | |
| parent | f5679e5a00f5ac37eb0c5e6cbb455de0aabc0ee6 (diff) | |
i2c: emev2: avoid race when unregistering slave client
[ 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>
Diffstat (limited to 'drivers/i2c/busses')
| -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 96bb4e749012..0218ba6eb26a 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; |