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H A DNCR5380.hdiff 25fcf94a2fa89dd3e73e965ebb0b38a2a4f72aa4 Sat Jun 08 20:19:11 CDT 2019 Finn Thain <fthain@telegraphics.com.au> Revert "scsi: ncr5380: Increase register polling limit"

This reverts commit 4822827a69d7cd3bc5a07b7637484ebd2cf88db6.

The purpose of that commit was to suppress a timeout warning message which
appeared to be caused by target latency. But suppressing the warning is
undesirable as the warning may indicate a messed up transfer count.

Another problem with that commit is that 15 ms is too long to keep
interrupts disabled as interrupt latency can cause system clock drift and
other problems.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 4822827a69d7 ("scsi: ncr5380: Increase register polling limit")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff 4822827a69d7cd3bc5a07b7637484ebd2cf88db6 Sun Oct 09 23:46:52 CDT 2016 Finn Thain <fthain@telegraphics.com.au> scsi: ncr5380: Increase register polling limit

If NCR5380_poll_politely() is called under irq lock, the polling time
limit is clamped to avoid a spike in interrupt latency. When not under
irq lock, the same polling time limit acts as the worst case delay
between schedule() calls.

During PDMA (under irq lock) I've found that the 10 ms time limit is
sometimes too short, and leads to the error message,
sd 0:0:0:0: [sda] tag#1 macscsi_pread: !REQ and !ACK

This particular target identifies itself as a QUANTUM DAYTONA514S. It
seems to be slower to assert ACK than the other targets I've tested.
This patch solves the problem by increasing the polling timeout.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>