From: Eric Moore <eric.moore@lsi.com>
To: James.Bottomley@HansenPartnership.com
Cc: linux-scsi@vger.kernel.org
Subject: [PATCH 2/10] mpt2sas : the sanity check in base_interrupt needs to be on dword boundary
Date: Tue, 21 Apr 2009 15:37:57 -0600 [thread overview]
Message-ID: <20090421213756.GC18563@lsil.com> (raw)
The poison sanity check on the reply_post_free register needs to be by 32bit,
not 64bit. The poison check is there because its possible that the driver read
the 1st 32bit before the 2nd 32bit has been written to by firmware. In other
words, this handles race between driver reading the 64 bit register, and it
being dma'd across pci memory from controller firmware as two 32bit pci writes.
Signed-off-by: Eric Moore <eric.moore@lsi.com>
diff -uarpN a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c 2009-03-16 08:52:29.000000000 -0600
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c 2009-04-09 16:36:40.000000000 -0600
@@ -636,6 +636,14 @@ _base_unmask_interrupts(struct MPT2SAS_A
static irqreturn_t
_base_interrupt(int irq, void *bus_id)
{
+ union reply_descriptor {
+ u64 word;
+ struct {
+ u32 low;
+ u32 high;
+ } u;
+ };
+ union reply_descriptor rd;
u32 post_index, post_index_next, completed_cmds;
u8 request_desript_type;
u16 smid;
@@ -656,7 +664,8 @@ _base_interrupt(int irq, void *bus_id)
completed_cmds = 0;
do {
- if (ioc->reply_post_free[post_index].Words == ~0ULL)
+ rd.word = ioc->reply_post_free[post_index].Words;
+ if (rd.u.low == UINT_MAX || rd.u.high == UINT_MAX)
goto out;
reply = 0;
cb_idx = 0xFF;
@@ -721,7 +730,7 @@ _base_interrupt(int irq, void *bus_id)
for (i = 0 ; i < completed_cmds; i++) {
post_index = post_index_next;
/* poison the reply post descriptor */
- ioc->reply_post_free[post_index_next].Words = ~0ULL;
+ ioc->reply_post_free[post_index_next].Words = ULLONG_MAX;
post_index_next = (post_index ==
(ioc->reply_post_queue_depth - 1))
? 0 : post_index + 1;
@@ -3068,7 +3077,7 @@ _base_make_ioc_operational(struct MPT2SA
/* initialize Reply Post Free Queue */
for (i = 0; i < ioc->reply_post_queue_depth; i++)
- ioc->reply_post_free[i].Words = ~0ULL;
+ ioc->reply_post_free[i].Words = ULLONG_MAX;
r = _base_send_ioc_init(ioc, VF_ID, sleep_flag);
if (r)
reply other threads:[~2009-04-21 21:36 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20090421213756.GC18563@lsil.com \
--to=eric.moore@lsi.com \
--cc=James.Bottomley@HansenPartnership.com \
--cc=linux-scsi@vger.kernel.org \
/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).