scsi: hisi_sas: Prevent parallel FLR and controller reset
If we issue a controller reset command during executing a FLR a hung task
may be found:
Call trace:
__switch_to+0x158/0x1cc
__schedule+0x2e8/0x85c
schedule+0x7c/0x110
schedule_timeout+0x190/0x1cc
__down+0x7c/0xd4
down+0x5c/0x7c
hisi_sas_task_exec+0x510/0x680 [hisi_sas_main]
hisi_sas_queue_command+0x24/0x30 [hisi_sas_main]
smp_execute_task_sg+0xf4/0x23c [libsas]
sas_smp_phy_control+0x110/0x1e0 [libsas]
transport_sas_phy_reset+0xc8/0x190 [libsas]
phy_reset_work+0x2c/0x40 [libsas]
process_one_work+0x1dc/0x48c
worker_thread+0x15c/0x464
kthread+0x160/0x170
ret_from_fork+0x10/0x18
This is a race condition which occurs when the FLR completes first.
Here the host HISI_SAS_RESETTING_BIT flag out gets of sync as
HISI_SAS_RESETTING_BIT is not always cleared with the hisi_hba.sem held, so
now only set/unset HISI_SAS_RESETTING_BIT under hisi_hba.sem .
Link: https://lore.kernel.org/r/1639579061-179473-7-git-send-email-john.garry@huawei.com
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2 files changed
