scsi: hisi_sas: Fix SATA devices missing issue during I_T nexus reset

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>

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 62080d0fad6ff394a076eff87dbbefdeb418472f..41ba22f6c7f051cbf58abcebf322cda7527a0c70 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1694,13 +1694,15 @@ 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);
        }