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| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2024-07-07 10:28:46 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-18 13:18:43 +0200 |
| commit | 4306fec13d4550d13e8208b1f9d32afa663dd9d6 (patch) | |
| tree | 74a48ea79e76e82027cb8fb0804290faf6872e09 | |
| parent | bfaf0990f14e2b14f4b2761e0b76544d310d21ab (diff) | |
| download | linux-4306fec13d4550d13e8208b1f9d32afa663dd9d6.tar.gz linux-4306fec13d4550d13e8208b1f9d32afa663dd9d6.tar.bz2 linux-4306fec13d4550d13e8208b1f9d32afa663dd9d6.zip | |
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@de.bosch.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com
Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index cef82b205c26..f8ac1489e1de 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; |