On Fri, Jan 20, 2017 at 08:12:12PM +0530, Chaitra P B wrote:
> Due existence of loop in the IO path our HBA will receive heavy IOs and
> also as driver is not updating the Reply Post Host Index frequently, So
> there will be a high chance that our Firmware unable to find any free entry
> in the Reply Post Descriptor Queue (i.e. Queue overflow occurs) and can
> observe 0x2100 firmware fault.
> So to fix this, we have defined a thresh hold value. After continuously
> processing this thresh hold number of reply descriptors driver will update
> the Reply Descriptor Host Index so that this thresh hold number of reply
> descriptors entries will be freed and these entries will be available for
> firmware and we won't observe this Firmware fault. We have defined this
> threshold value as 1/3rd of the hba queue depth.
>
> Signed-off-by: Chaitra P B <chaitra.basappa@xxxxxxxxxxxx>
> Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@xxxxxxxxxxxx>
> ---
> drivers/scsi/mpt3sas/mpt3sas_base.c | 19 +++++++++++++++++++
> 1 files changed, 19 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
> index 722fab9..a3fe1fb 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_base.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
> @@ -1040,6 +1040,25 @@ _base_interrupt(int irq, void *bus_id)
> reply_q->reply_post_free[reply_q->reply_post_host_index].
> Default.ReplyFlags & MPI2_RPY_DESCRIPT_FLAGS_TYPE_MASK;
> completed_cmds++;
> + /* Update the reply post host index after continuously
> + * processing the threshold number of Reply Descriptors.
> + * So that FW can find enough entries to post the Reply
> + * Descriptors in the reply descriptor post queue.
> + */
> + if (completed_cmds > ioc->hba_queue_depth/3) {
> + if (ioc->combined_reply_queue) {
> + writel(reply_q->reply_post_host_index |
> + ((msix_index & 7) <<
> + MPI2_RPHI_MSIX_INDEX_SHIFT),
> + ioc->replyPostRegisterIndex[msix_index/8]);
> + } else {
> + writel(reply_q->reply_post_host_index |
> + (msix_index <<
> + MPI2_RPHI_MSIX_INDEX_SHIFT),
> + &ioc->chip->ReplyPostHostIndex);
> + }
> + completed_cmds = 1;
> + }
> if (request_desript_type == MPI2_RPY_DESCRIPT_FLAGS_UNUSED)
> goto out;
> if (!reply_q->reply_post_host_index)
Do I understand it correctly that you fill the HBA's internal queue up to a
3rd and then kick it to start processing?
Thanks,
Johannes
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Johannes Thumshirn Storage
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SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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