The memories for the slot should be observed to be written prior to
observing the slot as ready.
Prior to commit 26fc0ea74f ("scsi: libsas: Drop SAS_TASK_AT_INITIATOR"),
we had a spin_lock() + spin_unlock() immediately before marking the slot as
ready. The spin_unlock() - with release semantics - caused the slot memory
to be observed to be written.
Now that the spin_lock() + spin_unlock() is gone, use a smp_wmb().
Link: https://lore.kernel.org/r/1652774661-12935-1-git-send-email-john.garry@huawei.com
Fixes: 26fc0ea74f ("scsi: libsas: Drop SAS_TASK_AT_INITIATOR")
Reported-by: Yihang Li <liyihang6@hisilicon.com>
Tested-by: Yihang Li <liyihang6@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Removing an ATA device via sysfs means that the device may not be found
through re-scanning:
root@ubuntu:/home/john# lsscsi
[0:0:0:0] disk SanDisk LT0200MO P404 /dev/sda
[0:0:1:0] disk ATA HGST HUS724040AL A8B0 /dev/sdb
[0:0:8:0] enclosu 12G SAS Expander RevB -
root@ubuntu:/home/john# echo 1 > /sys/block/sdb/device/delete
root@ubuntu:/home/john# echo "- - -" > /sys/class/scsi_host/host0/scan
root@ubuntu:/home/john# lsscsi
[0:0:0:0] disk SanDisk LT0200MO P404 /dev/sda
[0:0:8:0] enclosu 12G SAS Expander RevB -
root@ubuntu:/home/john#
The problem is that the rescan of the device may conflict with the device
in being re-initialized, as follows:
- In the rescan we call hisi_sas_slave_alloc() in store_scan() ->
sas_user_scan() -> [__]scsi_scan_target() -> scsi_probe_and_add_lunc()
-> scsi_alloc_sdev() -> hisi_sas_slave_alloc() -> hisi_sas_init_device()
In hisi_sas_init_device() we issue an IT nexus reset for ATA devices
- That IT nexus causes the remote PHY to go down and this triggers a bcast
event
- In parallel libsas processes the bcast event, finds that the phy is down
and marks the device as gone
The hard reset issued in hisi_sas_init_device() is unncessary - as
described in the code comment - so remove it. Also set dev status as
HISI_SAS_DEV_NORMAL as the hisi_sas_init_device() call.
Link: https://lore.kernel.org/r/1652354134-171343-4-git-send-email-john.garry@huawei.com
Fixes: 36c6b7613e ("scsi: hisi_sas: Initialise devices in .slave_alloc callback")
Tested-by: Yihang Li <liyihang6@hisilicon.com>
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
We have seen errors like this when a SATA device is probed:
[524.566298] hisi_sas_v3_hw 0000L74:02.0: erroneous completion iptt=4096 ...
[524.582827] sas: TMF task open reject failed 500e004aaaaaaaa00
Since commit 21c7e97247 ("scsi: hisi_sas: Disable SATA disk phy for
severe I_T nexus reset failure"), we issue an ATA softreset to disks after
a phy reset to ensure that they are in sound working order. If the
softreset is issued before the remote phy has come back up then the
softreset will fail (errors as above). Remedy this by waiting for the phy
to come back up after the reset.
Link: https://lore.kernel.org/r/1652354134-171343-3-git-send-email-john.garry@huawei.com
Tested-by: Yihang Li <liyihang6@hisilicon.com>
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The time of phyup not only depends on the controller but also the type of
disk connected. As an example, from experience, for some SATA disks the
amount of time from reset/power-on to receive the D2H FIS for phyup can
take upto and more than 10s sometimes. According to the specification of
some SATA disks such as ST14000NM0018, the max time from power-on to ready
is 30s.
Based on this the current timeout of phyup at 2s which is not enough. So
set the value as HISI_SAS_WAIT_PHYUP_TIMEOUT (30s) in
hisi_sas_control_phy().
For v3 hw there is a pre-existing workaround for a HW bug, being that we
issue a link reset when the OOB occurs but the phyup does not. The current
phyup timeout is HISI_SAS_WAIT_PHYUP_TIMEOUT. So if this does occur from
when issuing a phy enable or similar via hisi_sas_control_phy(), the
subsequent HW workaround linkreset processing calls hisi_sas_control_phy(),
but this will pend the original phy reset timing out, so it is safe.
Link: https://lore.kernel.org/r/1645703489-87194-3-git-send-email-john.garry@huawei.com
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It is possible that controller may become suspended between processing a
phyup interrupt and the event being processed by libsas. As such, we can't
ensure the controller is active when processing the phyup event - this may
cause the phyup event to be lost or other issues. To avoid any possible
issues, add pm_runtime_get_noresume() in phyup interrupt handler and
pm_runtime_put_sync() in the work handler exit to ensure that we stay
always active. Since we only want to call pm_runtime_get_noresume() for v3
hw, signal this will a new event, HISI_PHYE_PHY_UP_PM.
Link: https://lore.kernel.org/r/1639999298-244569-14-git-send-email-chenxiang66@hisilicon.com
Acked-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Most places that use asd_sas_port->phy_list are protected by spinlock
asd_sas_port->phy_list_lock, however there are still some places which miss
grabbing the lock. Add it in function hisi_sas_refresh_port_id() when
accessing asd_sas_port->phy_list. This carries a risk that list mutates
while at the same time dropping the lock in function
hisi_sas_send_ata_reset_each_phy(). Read asd_sas_port->phy_mask instead of
accessing asd_sas_port->phy_list to avoid this risk.
Link: https://lore.kernel.org/r/1639999298-244569-6-git-send-email-chenxiang66@hisilicon.com
Acked-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The OOB interrupt and phyup interrupt handlers may run out-of-order in high
CPU usage scenarios. Since the hisi_sas_phy.timer is added in
hisi_sas_phy_oob_ready() and disarmed in phy_up_v3_hw(), this out-of-order
execution will cause hisi_sas_phy.timer timeout to trigger.
To solve, protect hisi_sas_phy.timer and .attached with a lock, and ensure
that the timer won't be added after phyup handler completes.
Link: https://lore.kernel.org/r/1639579061-179473-8-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>
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>
A user may issue a control phy command from sysfs at any time, even if the
controller is resetting.
If a phy is disabled by hardreset/linkreset command before calling
get_phys_state() in the reset path, the saved phy state may be incorrect.
To avoid incorrectly recording the phy state, use hisi_hba.sem to ensure
that the controller reset may not run at the same time as when the phy
control function is running.
Link: https://lore.kernel.org/r/1639579061-179473-6-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>
If the softreset fails in the I_T reset, libsas will then continue to issue
a controller reset to try to recover.
However a faulty disk may cause the softreset to fail, and resetting the
controller will not help this scenario. Indeed, we will just continue the
cycle of error handle handling to try to recover.
So if the softreset fails upon certain conditions, just disable the phy
associated with the disk. The user needs to handle this problem.
Link: https://lore.kernel.org/r/1634041588-74824-5-git-send-email-john.garry@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When issuing a hardreset/linkreset/phy_set_linkrate from sysfs, the phy
will be disabled and re-enabled for the directly attached scenario.
It takes some time for the phy to come back up after re-enabling the phy.
If the controller becomes suspended while waiting for the phy to come back,
the phy up may be lost (along with the disk).
To solve this problem, wait for the phy up to occur with a timeout. Indeed
this is already done in hisi_sas_debug_I_T_nexus_reset() for local phys, so
just relocate the functionality to hisi_sas_control_phy().
Since the HA workqueue is drained when suspending the controller, and the
phy control function is called from the same workqueue, we can guarantee
that the controller will not be suspended during this period.
Link: https://lore.kernel.org/r/1634041588-74824-3-git-send-email-john.garry@huawei.com
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Some usage of del_timer() in the driver is potentially unsafe.
When running the sas_task->slow_task timer in
hisi_sas_exec_internal_tmf_task(), execution may be blocked in function
hisi_sas_task_exec(); so it is possible that the timer is running when the
callback to disable the timer is running. This could be dangerous, as we
immediately release resources which the timer callback uses after disabling
the timer. The same situation may be found at other sites, such as
_hisi_sas_internal_task_abort().
Change calls to del_timer() to del_timer_sync() as necessary, to ensure any
timer has finished when disabling.
Also remove calls to timer_pending() prior to del_timer() as it is not
necessary.
Link: https://lore.kernel.org/r/1629799260-120116-5-git-send-email-john.garry@huawei.com
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If an internal task abort timeout occurs, the controller has developed a
fault, and needs to be reset to be recovered.
When this occurs during error handling, the current policy is to allow
error handling to continue, and the inevitable nexus ha reset will handle
the required reset.
However various steps of error handling need to taken before this happens.
These also involve some level of HW interaction, which will also fail with
various timeouts.
Speed up this process by recording a HW fault bit for an internal abort
timeout - when this is set, just automatically error any HW interaction,
and essentially go straight to clear nexus ha (to reset the controller).
Link: https://lore.kernel.org/r/1623058179-80434-6-git-send-email-john.garry@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If an internal task abort timeout occurs, the controller has developed a
fault, and needs to be reset to be recovered. However if a timeout occurs
during SCSI error handling, issuing a controller reset immediately may
conflict with the error handling.
To handle internal abort in these two scenarios, only queue the reset when
not in an error handling function. In the case of a timeout during error
handling, do nothing and rely on the inevitable ha nexus reset to reset the
controller.
Link: https://lore.kernel.org/r/1623058179-80434-5-git-send-email-john.garry@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
