When we also are I2C slave, we need to disable runtime PM because the address detection mechanism needs to be active all the time. However, we can reenable runtime PM once the slave instance was unregistered. So, use pm_runtime_get_sync/put to achieve this, since it has proper refcounting. pm_runtime_allow/forbid is like a global knob controllable from userspace which is unsuitable here.
Unified · Split
| @@ -576,7 +576,7 @@ static int rcar_reg_slave(struct i2c_client *slave) · 575 unmodified lines | ||
| 576 | 576 | if (slave->flags & I2C_CLIENT_TEN) |
| 577 | 577 | return -EAFNOSUPPORT; |
| 578 | 578 | |
| 579 | − pm_runtime_forbid(rcar_i2c_priv_to_dev(priv)); | |
| 579 | + pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv)); | |
| 580 | 580 | |
| 581 | 581 | priv->slave = slave; |
| 582 | 582 | rcar_i2c_write(priv, ICSAR, slave->addr); |
| @@ -598,7 +598,7 @@ static int rcar_unreg_slave(struct i2c_client *slave) · 15 unmodified lines | ||
| 598 | 598 | |
| 599 | 599 | priv->slave = NULL; |
| 600 | 600 | |
| 601 | − pm_runtime_allow(rcar_i2c_priv_to_dev(priv)); | |
| 601 | + pm_runtime_put(rcar_i2c_priv_to_dev(priv)); | |
| 602 | 602 | |
| 603 | 603 | return 0; |
| 604 | 604 | } |