| Message ID | 20231006022233.3963590-1-zhangjian.3032@bytedance.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] i2c: aspeed: Fix i2c bus hang in slave read | expand |
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 <zhangjian.3032@bytedance.com> > Acked-by: Andi Shyti <andi.shyti@kernel.org> > Tested-by: Andrew Jeffery <andrew@codeconstruct.com.au> > Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au> > Applied to for-current, thanks!
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;
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 <zhangjian.3032@bytedance.com> Acked-by: Andi Shyti <andi.shyti@kernel.org> Tested-by: Andrew Jeffery <andrew@codeconstruct.com.au> Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au> --- 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(-)