From: Hannes Reinecke <hare@suse.de>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>,
James Bottomley <james.bottomley@hansenpartnership.com>,
Sumit Saxena <sumit.saxena@broadcom.com>,
linux-scsi@vger.kernel.org, Hannes Reinecke <hare@suse.de>,
Hannes Reinecke <hare@suse.com>
Subject: [PATCH 5/5] megaraid_sas: add mmio barrier after register writes
Date: Fri, 11 Nov 2016 10:44:52 +0100 [thread overview]
Message-ID: <1478857492-4581-6-git-send-email-hare@suse.de> (raw)
In-Reply-To: <1478857492-4581-1-git-send-email-hare@suse.de>
The megaraid_sas HBA only has a single register for I/O submission,
which will be hit pretty hard with scsi-mq. To ensure that the
PCI writes have made it across we need to add a mmio barrier
after each write; otherwise I've been seeing spurious command
completions and I/O stalls.
Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/megaraid/megaraid_sas_fusion.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index aba53c0..729a654 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -196,6 +196,7 @@ inline void megasas_return_cmd_fusion(struct megasas_instance *instance,
le32_to_cpu(req_desc->u.low));
writeq(req_data, &instance->reg_set->inbound_low_queue_port);
+ mmiowb();
#else
unsigned long flags;
--
1.8.5.6
next prev parent reply other threads:[~2016-11-11 9:45 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-11 9:44 [PATCH 0/5] megaraid_sas: scsi-mq support Hannes Reinecke
2016-11-11 9:44 ` [PATCH 1/5] megaraid_sas: switch to pci_alloc_irq_vectors Hannes Reinecke
2016-11-11 11:32 ` Sumit Saxena
2016-11-11 14:59 ` Hannes Reinecke
2016-11-14 12:33 ` Christoph Hellwig
2016-11-14 12:48 ` Christoph Hellwig
2016-11-11 9:44 ` [PATCH 2/5] megaraid_sas: avoid calling megasas_lookup_instance() Hannes Reinecke
2016-11-11 10:46 ` Sumit Saxena
2016-11-11 9:44 ` [PATCH 3/5] megaraid_sas: do not crash on invalid completion Hannes Reinecke
2016-11-11 11:51 ` Sumit Saxena
2016-11-11 15:07 ` Hannes Reinecke
2016-11-11 9:44 ` [PATCH 4/5] megaraid_sas: scsi-mq support Hannes Reinecke
2016-11-11 11:26 ` kbuild test robot
2016-11-11 11:56 ` Sumit Saxena
2016-11-14 11:07 ` Kashyap Desai
2016-11-11 9:44 ` Hannes Reinecke [this message]
2016-11-11 10:47 ` [PATCH 5/5] megaraid_sas: add mmio barrier after register writes Sumit Saxena
2016-11-18 15:53 ` Tomas Henzl
2016-11-18 16:48 ` Kashyap Desai
2016-11-21 15:57 ` Tomas Henzl
2016-11-30 6:14 ` Kashyap Desai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1478857492-4581-6-git-send-email-hare@suse.de \
--to=hare@suse.de \
--cc=hare@suse.com \
--cc=hch@lst.de \
--cc=james.bottomley@hansenpartnership.com \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=sumit.saxena@broadcom.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).