| Message ID | 1484923333-8509-4-git-send-email-chaitra.basappa@broadcom.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
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@broadcom.com> > Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com> > --- > 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
On Fri, Jan 20, 2017 at 8:40 PM, Johannes Thumshirn <jthumshirn@suse.de> wrote: > 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@broadcom.com> >> Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com> >> --- >> 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? No, driver will continuously process the reply descriptors from Reply Descriptor Post Queue (RDPQ) but will update it's Host Index (tail index) with the firmware after continuously processing 1/3rd of the HBA queue depth number of descriptors instead of updating it's host index only at after it see unused descriptor entry. So that firmware can always get enough free descriptors entries to post reply descriptors and won't see any 0x2100 fault which will occur if firmware doesn't find any free descriptor entry in the RDPQ queue. Thanks, Sreekanth > > Thanks, > Johannes > -- > Johannes Thumshirn Storage > jthumshirn@suse.de +49 911 74053 689 > SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg > GF: Felix Imendörffer, Jane Smithard, Graham Norton > HRB 21284 (AG Nürnberg) > Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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)