[PATCH 6.0 0630/1073] scsi: hisi_sas: Fix SATA devices missing issue during I_T nexus reset

Greg Kroah-Hartman
2022-12-28T16:13:25Z

From: Jie Zhan <zhanjie9@hisilicon.com>

[ Upstream commit 3c2673a09cf1181318c07b7dbc1bc532ba3d33e3 ]

SATA devices on an expander may be removed and not be found again when I_T
nexus reset and revalidation are processed simultaneously.

The issue comes from:

- Revalidation can remove SATA devices in link reset, e.g. in
hisi_sas_clear_nexus_ha().

- However, hisi_sas_debug_I_T_nexus_reset() polls the state of a SATA
device on an expander after sending link_reset, where it calls:
hisi_sas_debug_I_T_nexus_reset
sas_ata_wait_after_reset
ata_wait_after_reset
ata_wait_ready
smp_ata_check_ready
sas_ex_phy_discover
sas_ex_phy_discover_helper
sas_set_ex_phy

The ex_phy's change count is updated in sas_set_ex_phy(), so SATA
devices after a link reset may not be found later through revalidation.

A similar issue was reported in:
commit 0f3fce5cc77e ("[SCSI] libsas: fix ata_eh clobbering ex_phys via
smp_ata_check_ready")
commit 87c8331fcf72 ("[SCSI] libsas: prevent domain rediscovery competing
with ata error handling").

To address this issue, in hisi_sas_debug_I_T_nexus_reset(), we now call
smp_ata_check_ready_type() that only polls the device type while not
updating the ex_phy's data of libsas.

Fixes: 71453bd9d1bf ("scsi: hisi_sas: Use sas_ata_wait_after_reset() in IT nexus reset")
Signed-off-by: Jie Zhan <zhanjie9@hisilicon.com>
Link: https://lore.kernel.org/r/20221118083714.4034612-5-zhanjie9@hisilicon.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/hisi_sas/hisi_sas_main.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 33af5b8dede2..f4f9e5abee76 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1701,13 +1701,15 @@ static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
return rc;
}

+ /* Remote phy */
if (rc)
return rc;

- /* Remote phy */
if (dev_is_sata(device)) {
- rc = sas_ata_wait_after_reset(device,
- HISI_SAS_WAIT_PHYUP_TIMEOUT);
+ struct ata_link *link = &device->sata_dev.ap->link;
+
+ rc = ata_wait_after_reset(link, HISI_SAS_WAIT_PHYUP_TIMEOUT,
+ smp_ata_check_ready_type);
} else {
msleep(2000);
}
--
2.35.1