Hi Dan and Praveen, I found a patch titled "libsas: fix "sysfs group not found" warnings at port teardown time" by google, https://www.mail-archive.com/linux-scsi@xxxxxxxxxxxxxxx/msg39187.html I found the same warning calltrace in my platform, but I didn't find the patch changes in the latest kernel 4.5-rc2. So is this issue still in kernel ? I think your patch could fix this issue we found, but I'm worried about another problem. Now when unplug a disk LLDD report a event loss_of_singal sas_deform_port sas_unregister_domain_devices sas_unregister_dev sas_discover_event(dev->port, DISCE_DESTRUCT); sas_port_delete phy->port = NULL; and after your patch changes LLDD report a event loss_of_singal sas_deform_port sas_unregister_domain_devices sas_unregister_dev sas_discover_event(dev->port, DISCE_DESTRUCT); phy->port = NULL; ... sas_destruct_devices sas_port_delete //now we actually delete the port device, but we set phy->port = NULL; before this time. So if we hotplug the disk quickly, plug,unplug,plug, The new dmaed event(plug) would try to alloc and add a new port, but the old port device is still alive. Another calltrace would occur WARNING: CPU: 0 PID: 1038 at lib/kobject.c:240 kobject_add_internal+0x258/0x318() kobject_add_internal failed for port-0:0 with -EEXIST, don't try to register things with the same name in the same directory. CPU: 0 PID: 1038 Comm: kworker/u64:2 Tainted: G W 4.1.6+ #140 [<ffff800000089918>] dump_backtrace+0x0/0x124 [<ffff800000089a4c>] show_stack+0x10/0x1c [<ffff80000009fcbc>] warn_slowpath_fmt+0x4c/0x58 [<ffff8000003cdc04>] device_add+0x28c/0x5b8 [<ffff80000040d4ec>] sas_port_add+0x20/0xbc [<ffff80000040f3e8>] sas_porte_bytes_dmaed [<ffff8000000b5504>] process_one_work+0x13c/0x344 Because I am not a sas guy, so if you could comment this or post new patch, I would be thanks a lot! Thanks! Yijing. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
