When the `CONFIG_I2C_SLAVE` option is enabled and the device operates
as a slave, a situation arises where the master sends a START signal
without the accompanying STOP signal. This action results in a
persistent I2C bus timeout. The core issue stems from the fact that
the i2c controller remains in a slave read state without a timeout
mechanism. As a consequence, the bus perpetually experiences timeouts.
In this case, the i2c bus will be reset, but the slave_state reset is
missing.
Fixes: fee465150b45 ("i2c: aspeed: Reset the i2c controller when timeout occurs")
Signed-off-by: Jian Zhang <[email protected]>
Acked-by: Andi Shyti <[email protected]>
Tested-by: Andrew Jeffery <[email protected]>
Reviewed-by: Andrew Jeffery <[email protected]>
---
Changelog:
v3 - move to __aspeed_i2c_reg_slave.
v2 - remove the i2c slave reset and only move the
`bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE` to the aspeed_i2c_init.
---
drivers/i2c/busses/i2c-aspeed.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 5a416b39b818..28e2a5fc4528 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -749,6 +749,8 @@ static void __aspeed_i2c_reg_slave(struct aspeed_i2c_bus *bus, u16 slave_addr)
func_ctrl_reg_val = readl(bus->base + ASPEED_I2C_FUN_CTRL_REG);
func_ctrl_reg_val |= ASPEED_I2CD_SLAVE_EN;
writel(func_ctrl_reg_val, bus->base + ASPEED_I2C_FUN_CTRL_REG);
+
+ bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
}
static int aspeed_i2c_reg_slave(struct i2c_client *client)
@@ -765,7 +767,6 @@ static int aspeed_i2c_reg_slave(struct i2c_client *client)
__aspeed_i2c_reg_slave(bus, client->addr);
bus->slave = client;
- bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
spin_unlock_irqrestore(&bus->lock, flags);
return 0;
--
2.30.2
On Fri, Oct 06, 2023 at 10:22:33AM +0800, Jian Zhang wrote:
> When the `CONFIG_I2C_SLAVE` option is enabled and the device operates
> as a slave, a situation arises where the master sends a START signal
> without the accompanying STOP signal. This action results in a
> persistent I2C bus timeout. The core issue stems from the fact that
> the i2c controller remains in a slave read state without a timeout
> mechanism. As a consequence, the bus perpetually experiences timeouts.
>
> In this case, the i2c bus will be reset, but the slave_state reset is
> missing.
>
> Fixes: fee465150b45 ("i2c: aspeed: Reset the i2c controller when timeout occurs")
> Signed-off-by: Jian Zhang <[email protected]>
> Acked-by: Andi Shyti <[email protected]>
> Tested-by: Andrew Jeffery <[email protected]>
> Reviewed-by: Andrew Jeffery <[email protected]>
>
Applied to for-current, thanks!