Patch "i2c: rcar: reset controller is mandatory for Gen3+" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    i2c: rcar: reset controller is mandatory for Gen3+

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     i2c-rcar-reset-controller-is-mandatory-for-gen3.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit d387d93f597b7d632e173e56bd77cee0bdd05a97
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date:   Thu Sep 21 14:53:49 2023 +0200

    i2c: rcar: reset controller is mandatory for Gen3+
    
    [ Upstream commit 0e864b552b2302e40b2277629ebac79544a5c433 ]
    
    Initially, we only needed a reset controller to make sure RXDMA works at
    least once per transfer. Meanwhile, documentation has been updated. It
    now says that a reset has to be performed prior every transaction, even
    if it is non-DMA. So, make the reset controller a requirement instead of
    being optional. And bail out if resetting fails.
    
    Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
    Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
    Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
    Stable-dep-of: ea5ea84c9d35 ("i2c: rcar: ensure Gen3+ reset does not disturb local targets")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index b25a8e7ea2d20..5fd45a2402bc3 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -830,12 +830,10 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
 	/* Gen3 needs a reset before allowing RXDMA once */
 	if (priv->devtype == I2C_RCAR_GEN3) {
-		priv->flags |= ID_P_NO_RXDMA;
-		if (!IS_ERR(priv->rstc)) {
-			ret = rcar_i2c_do_reset(priv);
-			if (ret == 0)
-				priv->flags &= ~ID_P_NO_RXDMA;
-		}
+		priv->flags &= ~ID_P_NO_RXDMA;
+		ret = rcar_i2c_do_reset(priv);
+		if (ret)
+			goto out;
 	}
 
 	rcar_i2c_init(priv);
@@ -1090,15 +1088,6 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 		irqhandler = rcar_i2c_gen2_irq;
 	}
 
-	if (priv->devtype == I2C_RCAR_GEN3) {
-		priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
-		if (!IS_ERR(priv->rstc)) {
-			ret = reset_control_status(priv->rstc);
-			if (ret < 0)
-				priv->rstc = ERR_PTR(-ENOTSUPP);
-		}
-	}
-
 	/* Stay always active when multi-master to keep arbitration working */
 	if (of_property_read_bool(dev->of_node, "multi-master"))
 		priv->flags |= ID_P_PM_BLOCKED;
@@ -1108,6 +1097,16 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	if (of_property_read_bool(dev->of_node, "smbus"))
 		priv->flags |= ID_P_HOST_NOTIFY;
 
+	if (priv->devtype == I2C_RCAR_GEN3) {
+		priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+		if (IS_ERR(priv->rstc))
+			goto out_pm_put;
+
+		ret = reset_control_status(priv->rstc);
+		if (ret < 0)
+			goto out_pm_put;
+	}
+
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0)
 		goto out_pm_put;