Hi
On 04/21/18 22:11, Alexander Monakov wrote:
The interrupt handler dw_i2c_isr may be racing with i2c_dw_xfer_init.
Use disable_irq/enable_irq when setting up the adapter.
Cc: Ben Gardner <gardner.ben@xxxxxxxxx>
Cc: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Alexander Monakov <amonakov@xxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-master.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index fd36c39ddf4e..e7fd0e57ab1f 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -181,6 +181,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
/* Disable the adapter */
__i2c_dw_enable_and_wait(dev, false);
+ disable_irq(dev->irq);
/* If the slave address is ten bit address, enable 10BITADDR */
ic_con = dw_readl(dev, DW_IC_CON);
@@ -214,6 +215,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
+ enable_irq(dev->irq);
Are you seeing an issue here? Not sure about low level irq handling but
thinking here can we miss an interrupt between unmasking and enable_irq()?
I'm also thinking is there actually any issue if i2c_dw_isr() runs while
executing the i2c_dw_xfer_init() e.g. if the IRQ line is shared since
the i2c_dw_isr() is checking the DW_IC_ENABLE which is not enabled until
near at the end of i2c_dw_isr().
--
Jarkko
