6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
[ Upstream commit ea5ea84c9d3570dc06e8fc5ee2273eaa584aa3ac ]
R-Car Gen3+ needs a reset before every controller transfer. That erases
configuration of a potentially in parallel running local target
instance. To avoid this disruption, avoid controller transfers if a
local target is running. Also, disable SMBusHostNotify because it
requires being a controller and local target at the same time.
Fixes: 3b770017b03a ("i2c: rcar: handle RXDMA HW behaviour on Gen3")
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-rcar.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index f0724c8e4b219..185a5d60f1019 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -883,6 +883,10 @@ static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
{
int ret;
+ /* Don't reset if a slave instance is currently running */
+ if (priv->slave)
+ return -EISCONN;
+
ret = reset_control_reset(priv->rstc);
if (ret)
return ret;
@@ -1175,6 +1179,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
if (of_property_read_bool(dev->of_node, "smbus"))
priv->flags |= ID_P_HOST_NOTIFY;
+ /* R-Car Gen3+ needs a reset before every transfer */
if (priv->devtype >= I2C_RCAR_GEN3) {
priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (IS_ERR(priv->rstc)) {
@@ -1185,6 +1190,9 @@ static int rcar_i2c_probe(struct platform_device *pdev)
ret = reset_control_status(priv->rstc);
if (ret < 0)
goto out_pm_put;
+
+ /* hard reset disturbs HostNotify local target, so disable it */
+ priv->flags &= ~ID_P_HOST_NOTIFY;
}
ret = platform_get_irq(pdev, 0);
--
2.43.0
