>> In this patch, we try to solve these issues in following steps: >> 1. create a new workqueue used to run sas event work, instead of scsi host workqueue, >> because we may block sas event work, we cannot block the normal scsi works. >> When libsas receive a phy down event, sas_deform_port would be called, and now we >> block sas_deform_port and wait for destruction work finish, in sas_destruct_devices, >> we may wait ata error handler, it would take a long time, so if do all stuff in scsi >> host workq, libsas may block other scsi works too long. >> 2. create a new workqueue used to run sas discovery events work, instead of scsi host >> workqueue, because in some cases, eg. in revalidate domain event, we may unregister >> a sas device and discover new one, we must sync the execution, wait the remove process >> finish, then start a new discovery. So we must put the probe and destruct discovery >> events in a new workqueue to avoid deadlock. >> 3. introudce a asd_sas_port level wait-complete and a sas_discovery level wait-complete >> we use former wait-complete to achieve a sas event atomic process and use latter to >> make a sas discovery sync. >> 4. remove disco_mutex in sas_revalidate_domain, since now sas_revalidate_domain sync >> the destruct discovery event execution, it's no need to lock disco mutex there. > > The way you've written the changelog suggests this patch should be split > into 4 patches, each one taking care of one of your change items. I will split it in next version. Thanks! Yijing. >
