Commit b288daf8 authored Nov 13, 2018 by Wolfram Sang Committed by Greg Kroah-Hartman Dec 21, 2018

i2c: rcar: check bus state before reinitializing



[ Upstream commit 0b57436f15bf40e432487086c4f2d01fd3529393 ]

We should check the bus state before reinitializing the IP core.
Otherwise, the internal bus busy state which also tracks multi-master
activity is lost.

Credits go to the Renesas BSP team for suggesting this change.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: ae481cc1 ("i2c: rcar: fix resume by always initializing registers before transfer")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 53e0d8ec

drivers/i2c/busses/i2c-rcar.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -779,6 +779,11 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,

		pm_runtime_get_sync(dev);

		/* Check bus state before init otherwise bus busy info will be lost */
		ret = rcar_i2c_bus_barrier(priv);
		if (ret < 0)
		goto out;

		/* Gen3 needs a reset before allowing RXDMA once */
		if (priv->devtype == I2C_RCAR_GEN3) {
		priv->flags \|= ID_P_NO_RXDMA;
		@@ -791,10 +796,6 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,

		rcar_i2c_init(priv);

		ret = rcar_i2c_bus_barrier(priv);
		if (ret < 0)
		goto out;

		for (i = 0; i < num; i++)
		rcar_i2c_request_dma(priv, msgs + i);