These patches address some issues with positoin lost handling which
where introduced by commit 9604eea5bd3a ("scsi: st: Add third party
poweron reset handling"). That commit added code which detected any
unexpected power on/reset unit attention to st_chk_results() and
correclty set pos_unknown in the driver.
However, the aforementioned changes is catching POR UAs that are
expected as well as those that are unexpected as st_chk_results() sets
pos_unknown every time a POR UA is seen. This results in a change of
behavior that is confusing as some tape drives can set a POR UA when the
system reboots, the driver reloads, or a tape is reloaded. This results
in regressions as MTIOGET now fails following and kind of reset.
These issues are documented in the kernel bugzilla:
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219419
A reproducer test script can be found at:
Link: https://github.com/johnmeneghini/tape_tests
John Meneghini (3):
scsi: st: instrument the pos_unknown code
scsi: st: clear was_reset when CHKRES_NEW_SESSION
scsi: st: clear pos_unknown when the por ua is expected
drivers/scsi/st.c | 63 ++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 54 insertions(+), 9 deletions(-)
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2.47.0
