[Bug 205461] New: Power-On-Reset Prevents Successful Receive Diagnostics Command in SES Module.

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https://bugzilla.kernel.org/show_bug.cgi?id=205461

            Bug ID: 205461
           Summary: Power-On-Reset Prevents Successful Receive Diagnostics
                    Command in SES Module.
           Product: SCSI Drivers
           Version: 2.5
    Kernel Version: 5.4-rc6
          Hardware: All
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Other
          Assignee: scsi_drivers-other@kernel-bugs.osdl.org
          Reporter: ssiwinski@attotech.com
        Regression: No

Created attachment 285817
  --> https://bugzilla.kernel.org/attachment.cgi?id=285817&action=edit
Power-On-Reset Prevents Successful Receive Diagnostics Command

Overview:

When booting an SES device connected to an ATTO SAS HBA, the SES module issues
a 'Receive Diagnostics' command that fails with check condition power-on-reset
and is not retried by the SES module.

Interestingly, when booting an SES device connected to an LSI SAS HBA, the
Receive Diagnostics succeeds due to LSI issuing a 'Mode Sense' command prior to
the SES module sending the 'Receive Diagnostics' that clears the check
condition power-on-reset.

Us (ATTO) does not want to have to issue a command to clear the check condition
power-on-reset unless we must. There is no spec that states this is what must
happen and seems to be a case that the SES module should handle.


Steps to Reproduce:

With an ATTO SAS HBA:
Connect an SES device to an ATTO SAS HBA, then power on the SES device. 

With an LSI SAS HBA:
I was able to reproduce this issue with an LSI SAS HBA and other SAS HBAs by
unloading the SES module, issuing a target reset to the SES device, then
re-loading the SES module.


Actual Results:

In the system log you will see

[  953.809858] scsi 7:0:0:0: Power-on or device reset occurred
[  953.809891] scsi 7:0:0:0: Failed to get diagnostic page 0x1
[  953.809931] scsi 7:0:0:0: Failed to bind enclosure -19

This can also be observed in the "sas_poweron_atto.scs" SAS trace.


Expected Results:

The Receive Diagnostics command to succeed and no error logged to the system
log.

This can also be observed in a SAS trace of an SES device connected to an LSI
HBA, where the 'Receive Diagnostics' command succeeds due to the check
condition power-on-reset being cleared by the 'Mode Sense' command issued prior
to the 'Receive Diagnostics'. (Trace can be provided upon request).


Additional Information:

It appears that I cannot attach SAS traces from both ATTO and LSI devices, so I
have attached the trace while connected to an ATTO SAS HBA that clearly
exhibits the error. If both traces are needed, I can provide them by a
different means.

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