I have developed a sample USB mass storage driver. Using this driver, I can mount file system on my CF card, and can read/write small files to/from CF card. However, the driver crashes while reading/writing large files. >From kernel stack trace, it seems there is some synchronization issue with interrupts. I see kernel stack something like this: soft lockup detected on CPU#0 softlockup_tick update_process_timers tick_periodic tick_handle_periodic smp_apic_timer_interrupt apic_timer_interrupt add_to_page_cache add_to_page_cache_lru do_generic_mapping_read file_read_actor do_sync_read autoremove_wake_function __sched_text_start mutex_lock vfs_read copy_to_user do_sync_read sys_read sysenter_past_esp Looking at the stack trace, it seems, some locking mechanism is required. I am referring to LDD3 chapter 13 (USB Drivers) and chapter 16 (Block drivers). The driver does USB read/write as follows: my_request_queue_function check if request is read or write allocate and fill urb (using req->sector and req->current_nr_sectors) submit urb wait to complete copy data to req->buffer during this process, I have not taken any lock. Can someone give some hint, if some lock is required here? I do not submit any urb in complete function of usb_fill_bulk_urb. I am not able to get which other part can be executed in interrupt context (if I am right, request queue function is not called in interrupt context). Any hints would be appreciated. -Lal -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
