The I2C driver for my Atom E3845 board has been broken since 4.9. These kernel logs show up whenever am I2C transaction is attempted. i2c-designware-pci 0000:00:18.3: timeout in disabling adapter i2c-designware-pci 0000:00:18.3: timeout waiting for bus ready The root issue is that the I2C port takes a while to enable and somewhere along the way, the 'enable-and-wait' approach to enabling the adapter was changed to 'enable'. That caused the driver and hardware to get out of sync and fail. I have tested this patch on 4.14 and 4.15. Signed-off-by: Ben Gardner <gardner.ben@xxxxxxxxx> --- drivers/i2c/busses/i2c-designware-master.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index ae69188..55926ef 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -209,7 +209,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) i2c_dw_disable_int(dev); /* Enable the adapter */ - __i2c_dw_enable(dev, true); + __i2c_dw_enable_and_wait(dev, true); /* Clear and enable interrupts */ dw_readl(dev, DW_IC_CLR_INTR); -- 2.7.4
