| Message ID | 20240703071625.5389-1-wsa+renesas@sang-engineering.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | [RFC] i2c: rcar: bring hardware to known state when probing | expand |
Hi Wolfram, On Wed, Jul 03, 2024 at 09:12:03AM GMT, Wolfram Sang wrote: > Probably due to a lot of refactorization, the hardware was not brought > into a known state in probe. 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 > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Do we need the Fixes tag here? > --- > > Here is my proposal to fix the issue reported by Dirk. Build tested. > I can do proper testing on HW only tomorrow. But so you know already... Looks reasonable. If testing is fine I can queue this up for this week's pull request. > It is strange to add another "_slave" function to the driver while I > work on removing such language from I2C somewhere else. "Consistency" is > the answer here. The driver will be converted as well. But then as a > whole. Ack! Thanks, Andi
> Do we need the Fixes tag here? We can add the initial commit for this driver. That means the commit message is wrong because refactorization is not the culprit. So, I will resend with Fixes-tag and updated commit message. > Looks reasonable. If testing is fine I can queue this up for this > week's pull request. First testing looks good. I will do some more.
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 828aa2ea0fe4..00a885205075 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -257,6 +257,14 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) } } +static void rcar_i2c_init_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; @@ -1033,11 +1041,8 @@ 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_init_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; @@ -1152,7 +1157,9 @@ 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_init_slave(priv); if (priv->devtype < I2C_RCAR_GEN3) { irqflags |= IRQF_NO_THREAD;
Probably due to a lot of refactorization, the hardware was not brought into a known state in probe. 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 Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- Here is my proposal to fix the issue reported by Dirk. Build tested. I can do proper testing on HW only tomorrow. But so you know already... It is strange to add another "_slave" function to the driver while I work on removing such language from I2C somewhere else. "Consistency" is the answer here. The driver will be converted as well. But then as a whole. drivers/i2c/busses/i2c-rcar.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)