* Grygorii Strashko <[email protected]> [150826 11:01]: > Now Kernel fails to boot 50% of times (form build to build) with > RT-patchset applied due to the following race - on late boot > stages deferred_probe_work_func races with omap_device_late_ini > > late_initcall > - deferred_probe_initcal() tries to re-probe all pending driver's probe. > [In general, It's NOT expected to probe any other built-in drivers after > deferred_probe_initcal() is finished, because most of > late_initcall_sync/late_initcall functions expected that all driver > or probed or deferred already.] > > - later on, some driver is probing in this case It's could cpsw.c > (but could be any other drivers) > cpsw_init > - platform_driver_register > - really_probe > - driver_bound > - driver_deferred_probe_trigger > and boot proceed. > So, at this moment we have deferred_probe_work_func scheduled. > > late_initcall_sync > - omap_device_late_init > - omap_device_idle > > CPU1 CPU2 > - deferred_probe_work_func > - really_probe > - omap_hsmmc_probe > - pm_runtime_get_sync > late_initcall_sync > - omap_device_late_init > if (od->_driver_status != > BUS_NOTIFY_BOUND_DRIVER) { > if (od->_state == > OMAP_DEVICE_STATE_ENABLED) { > - > omap_device_idle [ops - IP is disabled, ] > - [fail] > - pm_runtime_put_sync > - omap_hsmmc_runtime_suspend [ooops!]
OK idling of unclaimed devices should not happen for deferred probe, it should only happen when there's no driver and no probing happening. > Lets remove just remove omap_device_late_init completely as suggested > by Tero Kristo: > > "How about remove omap_device_late_init call completely. I don't think > it does anything useful at the moment; none of the omap devices get > enabled outside runtime_pm, so there should be no need to explicitly > disable the devices." I think this is still needed from PM point of view as otherwise we don't idle any devices that don't have a driver available. Or am I missing something? To me it seems the bug is relying on the BUS_NOTIFY_BOUND_DRIVER is not set in the deferred probe case. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
