Re: [PATCH v2 3/3] scsi/ncr5380: Improve interrupt latency during PIO tranfers

Martin K. Petersen
2016-09-14T18:12:29Z

>>>>> "Finn" == Finn Thain <fthain@telegraphics.com.au> writes:

Finn> Large PIO transfers are broken up into chunks to try to avoid
Finn> disabling local IRQs for long periods. But IRQs are still disabled
Finn> for too long and this causes SCC FIFO overruns during serial port
Finn> transfers.

Finn> This patch reduces the PIO chunk size to reduce interrupt latency
Finn> to something on the order of milliseconds, at the expense of
Finn> additional CPU overhead from extra iterations of the
Finn> NCR5380_main() loop.

Applied to 4.9/scsi-queue.

--
Martin K. Petersen Oracle Linux Engineering