Commit 2a2d95e9 authored by Mika Westerberg's avatar Mika Westerberg Committed by Wolfram Sang

i2c: designware: always clear interrupts before enabling them

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: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
parent e6f34cea
...@@ -383,7 +383,8 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) ...@@ -383,7 +383,8 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
/* Enable the adapter */ /* Enable the adapter */
__i2c_dw_enable(dev, true); __i2c_dw_enable(dev, true);
/* Enable interrupts */ /* Clear and enable interrupts */
i2c_dw_clear_int(dev);
dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK); dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK);
} }
......
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