Hi If I don't have disabled irqs I can use API i2c_smbus_write_byte in order to perform i2c transaction. But how to make i2c transaction if I have disabled irq? Is any built-in function which lets such operation, where there is some polling implemented? The background is that I do i2c transaction in restart handler (some i2c transaction to hot swap controller) in order to reset board. And linux before entering restart handler list disable interrupts. There is a function to enable back interrupts but in company in which I am working engineers reviewed it and said "it is not allowed, restart must be performed when interrupts are disabled".