3.6.11.5 stable review patch. If anyone has any objections, please let me know. ------------------ From: Mika Westerberg [ Upstream commit 2a2d95e9d6d29e726cc294b65391917ed2e32bf4 ] If the I2C bus is put to a low power state by an ACPI method it might pull the SDA line low (as its power is removed). Once the bus is put to full power state again, the SDA line is pulled back to high. This transition looks like a STOP condition from the controller point-of-view which sets STOP detected bit in its status register causing the driver to fail subsequent transfers. Fix this by always clearing all interrupts before we start a transfer. Signed-off-by: Mika Westerberg Signed-off-by: Wolfram Sang Cc: stable@kernel.org Signed-off-by: Steven Rostedt --- drivers/i2c/busses/i2c-designware-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 37b1221..534fc13 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -360,7 +360,8 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) /* Enable the adapter */ dw_writel(dev, 1, DW_IC_ENABLE); - /* Enable interrupts */ + /* Clear and enable interrupts */ + i2c_dw_clear_int(dev); dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK); } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/