>From [EMAIL PROTECTED] Mon Feb 9 23:12:23 2004
>> Especially if the sense code is NO SENSE. Logically that should
>> indicate the driver needed to find out whether or not there was error,
>> and it learned that there wasn't.
>For tape drives, sense key == NO SENSE is not equivalent to no error to
>report. Often a tape drive returns a sense key of NO SENSE but with one
>of the other bits (EOM, FILEMARK, ILI) set in the same byte as the sense
>key. There are also some ASC/ASCQ combinations that go with a sense key
>of NO SENSE but without any of the EOM, FILEMARK, or ILI bits set.
>On the other hand, some tape drives set the EOM bit in unsolicited
>request sense data just to report the position of the tape, so the EOM
>bit being set isn't necessarily an indicator that there was an error.
>However, ASC/ASCQ should be nonzero when the EOM bit is set because of
>an error.
>I recommend defining "no error" to be:
>(sense_data[2] & 0xaf) == 0x00 && /* Filemark 0, ignore EOM, ILI 0, NO
>SENSE */
>sense_data[12] == 0x00 && /* ASC */
>sense_data[13] == 0x00 /* ASCQ */
>This should work for most devices that I have encountered.
Sounds OK.
It would be sufficient to clear Byte 0 of the sense data in this case,
as a correctly written program like libscg first checks whether
the SCSI sense data is in the expected extended sense format.
Note: As libscg is now 18 years old, it also supports the non-extended
sense format. This is why byte 0 in the sense data needs to be cleared
completely.
Jörg
--
EMail:[EMAIL PROTECTED] (home) Jörg Schilling D-13353 Berlin
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