Jie Zhan e933c28aa5 scsi: hisi_sas: Fix SATA devices missing issue during I_T nexus reset
[ 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>
2023-02-25 11:25:39 +01:00
2022-09-28 09:02:20 +02:00
2022-09-28 09:02:20 +02:00
2022-10-10 12:00:45 -07:00
2023-02-22 12:59:56 +01:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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