From: Alexander Stein alexander.stein@ew.tq-group.com
[ Upstream commit 1c7885004567e8951d65a983be095f254dd20bef ]
When reading from I2C, the Tx watermark is set to 0. Unfortunately the TDF (transmit data flag) is enabled when Tx FIFO entries is equal or less than watermark. So it is set in every case, hence the reset default of 1. This results in the MSR_RDF _and_ MSR_TDF flags to be set thus trying to send Tx data on a read message. Mask the IRQ status to filter for wanted flags only.
Fixes: a55fa9d0e42e ("i2c: imx-lpi2c: add low power i2c bus driver") Signed-off-by: Alexander Stein alexander.stein@ew.tq-group.com Tested-by: Emanuele Ghidoli emanuele.ghidoli@toradex.com Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-imx-lpi2c.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c index e86801a631206..ca4d554126579 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -515,10 +515,14 @@ static int lpi2c_imx_xfer(struct i2c_adapter *adapter, static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id) { struct lpi2c_imx_struct *lpi2c_imx = dev_id; + unsigned int enabled; unsigned int temp;
+ enabled = readl(lpi2c_imx->base + LPI2C_MIER); + lpi2c_imx_intctrl(lpi2c_imx, 0); temp = readl(lpi2c_imx->base + LPI2C_MSR); + temp &= enabled;
if (temp & MSR_RDF) lpi2c_imx_read_rxfifo(lpi2c_imx);