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authorWolfram Sang <wsa+renesas@sang-engineering.com>2019-08-08 21:39:10 +0200
committerWolfram Sang <wsa@the-dreams.de>2019-08-14 14:49:36 +0200
commit7b814d852af6944657c2961039f404c4490771c0 (patch)
treed9c018472072e09d33fc9a0e7de6a46211b4e2da /drivers
parentMAINTAINERS: i2c-imx: take over maintainership (diff)
downloadlinux-dev-7b814d852af6944657c2961039f404c4490771c0.tar.xz
linux-dev-7b814d852af6944657c2961039f404c4490771c0.zip
i2c: rcar: 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: de20d1857dd6 ("i2c: rcar: 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')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index d39a4606f72d..531c01100b56 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -139,6 +139,7 @@ struct rcar_i2c_priv {
enum dma_data_direction dma_direction;
struct reset_control *rstc;
+ int irq;
};
#define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent)
@@ -861,9 +862,11 @@ static int rcar_unreg_slave(struct i2c_client *slave)
WARN_ON(!priv->slave);
+ /* disable irqs and ensure none is running before clearing ptr */
rcar_i2c_write(priv, ICSIER, 0);
rcar_i2c_write(priv, ICSCR, 0);
+ synchronize_irq(priv->irq);
priv->slave = NULL;
pm_runtime_put(rcar_i2c_priv_to_dev(priv));
@@ -918,7 +921,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
struct i2c_adapter *adap;
struct device *dev = &pdev->dev;
struct i2c_timings i2c_t;
- int irq, ret;
+ int ret;
/* Otherwise logic will break because some bytes must always use PIO */
BUILD_BUG_ON_MSG(RCAR_MIN_DMA_LEN < 3, "Invalid min DMA length");
@@ -984,10 +987,10 @@ static int rcar_i2c_probe(struct platform_device *pdev)
pm_runtime_put(dev);
- irq = platform_get_irq(pdev, 0);
- ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv);
+ priv->irq = platform_get_irq(pdev, 0);
+ ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, dev_name(dev), priv);
if (ret < 0) {
- dev_err(dev, "cannot get irq %d\n", irq);
+ dev_err(dev, "cannot get irq %d\n", priv->irq);
goto out_pm_disable;
}