Hi, On 3/9/19 7:13 AM, Christopher Heiny wrote: > I'm not sure this is a safe action, due to a race condition with the > actual IRQ handler (rmi_process_interrupt_requests from rmi_driver.c). > Remember that reading the IRQ status register clears all the IRQ bits. > So you're faced with this possible scenario: > - ATTN asserted, indicating new data in IRQ status register > - rmi_driver_set_irq_bits called > - rmi_driver_set_irq_bits reads IRQ status, clearing bits > - rmi_process_interrupt_requests called > - rmi_process_interrupt_request reads IRQ status, sees no > bits set, nested IRQs are not handled > This could lead to loss of data or inconsistent system state > information. For example, a button up or down event may be lost, with > consequent weird behavior by the user interface. rmi_driver_set_irq_bits is only called to config and enable specific functions of RMI. Reading IRQ status before set irqs is supposed to clear spam data/irq status. spam data make probe/detect touchpad/trackpoint fail. rmi_smb_resume -> rmi_driver_reset_handler -> fn-config -> clear_irq_bits -> set_irq_bits -> enable_irq -> irq_handler -> rmi_process_interrupt_requests set_irq_bits will not be in interrupt context, it enables IRQ bits of RMI. Regards, Aaron
