scsi: ncr5380: Simplify register polling limit

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When polling a device register under irq lock the polling loop terminates
after a given number of jiffies. Make this timeout independent of the HZ
setting.

All 5380 drivers benefit from this patch, which optimizes the PIO fast
path, because they all use PIO transfers (for phases other than DATA IN
and DATA OUT). Some cards support only PIO transfers (even for DATA
phases). CPU cycles are scarce on some of these systems, so a small
improvement here makes a big difference.

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>

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Finn Thain 2016-10-10 00:46:52 -04:00 • committed by Martin K. Petersen

parent abd12b0929

commit d4408dd7ec

2 changed files with 8 additions and 7 deletions

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10

drivers/scsi/NCR5380.c

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5

drivers/scsi/NCR5380.h

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