This is a note to let you know that I've just added the patch titled
i2c: rcar: bring hardware to known state when probing
to the 6.6-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-bring-hardware-to-known-state-when-probing.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2f812cabfd9819bace63e5b833786c0f713f0d1f
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date: Sun Jul 7 10:28:46 2024 +0200
i2c: rcar: bring hardware to known state when probing
[ Upstream commit 4e36c0f20cb1c74c7bd7ea31ba432c1c4a989031 ]
When probing, the hardware is not brought into a known state. This may
be a problem when a hypervisor restarts Linux without resetting the
hardware, leaving an old state running. Make sure the hardware gets
initialized, especially interrupts should be cleared and disabled.
Reported-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx>
Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@xxxxxxxxxxxx
Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index a32a93f9a60d0..2fec6cb09757a 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -223,6 +223,14 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
}
+static void rcar_i2c_reset_slave(struct rcar_i2c_priv *priv)
+{
+ rcar_i2c_write(priv, ICSIER, 0);
+ rcar_i2c_write(priv, ICSSR, 0);
+ rcar_i2c_write(priv, ICSCR, SDBS);
+ rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */
+}
+
static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
{
int ret;
@@ -975,11 +983,8 @@ static int rcar_unreg_slave(struct i2c_client *slave)
/* ensure no irq is running before clearing ptr */
disable_irq(priv->irq);
- rcar_i2c_write(priv, ICSIER, 0);
- rcar_i2c_write(priv, ICSSR, 0);
+ rcar_i2c_reset_slave(priv);
enable_irq(priv->irq);
- rcar_i2c_write(priv, ICSCR, SDBS);
- rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */
priv->slave = NULL;
@@ -1092,7 +1097,9 @@ static int rcar_i2c_probe(struct platform_device *pdev)
goto out_pm_disable;
}
- rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */
+ /* Bring hardware to known state */
+ rcar_i2c_init(priv);
+ rcar_i2c_reset_slave(priv);
if (priv->devtype < I2C_RCAR_GEN3) {
irqflags |= IRQF_NO_THREAD;
