> I think the following sequence needs to be implemented to make this > safe, i.e., after 'synchronize_irq', no further slave interrupt will be > fired. > > In 'bcm_iproc_i2c_unreg_slave': > > 1. Set an atomic variable 'unreg_slave' (I'm bad in names so please come > up with a better name than this) > > 2. Disable all slave interrupts > > 3. synchronize_irq > > 4. Set slave to NULL > > 5. Erase slave addresses What about this in unreg_slave? 1. disable_irq() This includes synchronize_irq() and avoids the race. Because irq will be masked at interrupt controller level, interrupts coming in at the I2C IP core level should still be pending once we reenable the irq. 2. disable all slave interrupts 3. enable_irq() 4. clean up the rest (pointer, address) Or am I overlooking something?