On 07/09/2023 20:29, Pierre-Louis Bossart wrote: >> I think find all this very confusing, because there is no workqueue used >> in the remove steps. The workqueue is only used ONCE during the probe. > > Maybe we should just remove any references to workqueues, and have > > probe_start (cannot run in a wq) > probe (may run in a wq) > remove (cannot run in a wq, needs to call cancel_work_sync() if the > probe runs in a wq) > remove_last (cannot run in a wq, releases all resources acquired in > probe_start) > > Or something similar that shows the symmetry between steps and when the > wq is allowed. What we have atm: snd_sof_probe - might be called from wq snd_sof_remove - might be called from wq (cleans up the snd_sof_probe step) We want a callbacks for hardware/device probing, right, split the snd_sof_probe (and remove) to be able to support a sane level of deferred probing support. With that in mind: snd_sof_device_probe - Not called from wq (to handle deferred probing) snd_sof_probe - might be called from wq snd_sof_remove - might be called from wq (cleans up the snd_sof_probe step) snd_sof_device_remove - Not called from wq (to up the snd_sof_device_probe step) Naming option: s/device/hardware However, I think the snd_sof_device_remove itself is redundant and we might not need it at all as in case we have wq and there is a failure in there we do want to release resources as much as possible. The module will be kept loaded (no deferred handling in wq) and that might block PM, other devices to behave correctly. Iow, if the wq has failure we should do a cleanup to the best effort to reach a level like the driver is not even loaded. Doable? I thin it is. -- Péter
