Re: POWER MODE and sat,12 again

Christian,

>  The SAT layer in this (very old?) Linux kernel is apparently broken.
>  It returns sense key 4 (HARDWARE ERROR) which means that the SAT ATA
>  PASS-THROUGH(12) command has failed.
>  The kernel should return 1 (RECOVERED ERROR) if the command succeeded
>  and output registers are returned in SCSI sense data.

>  Here similar problem with SMART STATUS of an USB bridge:
>  http://www.smartmontools.org/ticket/548#comment:3

>  Does the SMART STATUS (smartctl -H) work with this kernel?
Yes,
  # smartctl -H -d sat,12 /dev/sdb
  smartctl 5.43 2012-06-30 r3573 [i686-linux-2.6.32-573.1.1.el6.i686] (local build)
  Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net
  
  === START OF READ SMART DATA SECTION ===
  SMART overall-health self-assessment test result: PASSED
  Warning: This result is based on an Attribute check.
  Please note the following marginal Attributes:
  ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  190 Airflow_Temperature_Cel 0x0022   067   041   045    Old_age   Always   In_the_past 33 (0 13 33 33 0)

> Did you check -d sat ?
Yes, It doesn't work.

These are relatively up to date kernels, maintained in the RedHat 
fashion (i.e changes are retrofitted to the base kernel release). 
smart{d,ctl} have worked with sat,12 on this disk+enclosure without 
problems in a sequence of kernels that ended with kernel 2.6.32-504.30.3.el6. 
But now suddenly with the new kernel 2.6.32-573.1.1.el6 there are 
problems (which eerely look like the problems we addressed in 2009).

The strange thing is that only some SAT ATA PASS-THROUGH(12) commands
seem to fail, hdparm fails with "-S 180 --prefer-ata12" but works with 
"-I --prefer-ata12" and smart{d,ctl} fail with "-n" but otherwise
work. In both failed cases POWER MODE is accessed. I haven't discovered 
any other sat,12 accesses that caused problems. Is there something 
special with accessing POWER MODE?

Any advice on how to proceed? Thanks, AG

-- 
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   Alfred Ganz					alfred-ganz:at:agci.com
   AG Consulting				(203) 624-9667
   440 Prospect Street # 11
   New Haven, CT 06511
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