public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Robin Holt <holt@sgi.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Robin Holt <holt@sgi.com>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
	Jack Steiner <steiner@sgi.com>
Subject: [patch] sgi-xp: nested calls to spin_lock_irqsave()
Date: Wed, 27 Jun 2012 08:51:55 -0500	[thread overview]
Message-ID: <20120627135155.GA3464@sgi.com> (raw)


The code here has a nested spin_lock_irqsave().  It's not needed since
IRQs are already disabled and it causes a problem because it means that
IRQs won't be enabled again at the end.  The second call to
spin_lock_irqsave() will overwrite the value of irq_flags and we can't
restore the proper settings.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Robin Holt <holt@sgi.com>

diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
index 17bbacb..87b251a 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -452,9 +452,9 @@ xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
 
 		if (msg->activate_gru_mq_desc_gpa !=
 		    part_uv->activate_gru_mq_desc_gpa) {
-			spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+			spin_lock(&part_uv->flags_lock);
 			part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
-			spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+			spin_unlock(&part_uv->flags_lock);
 			part_uv->activate_gru_mq_desc_gpa =
 			    msg->activate_gru_mq_desc_gpa;
 		}

             reply	other threads:[~2012-06-27 13:51 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-27 13:51 Robin Holt [this message]
2012-06-28 22:03 ` [patch] sgi-xp: nested calls to spin_lock_irqsave() Andrew Morton
2012-06-29  6:44   ` Dan Carpenter
  -- strict thread matches above, loose matches on Subject: below --
2011-12-15  6:48 Dan Carpenter
2011-12-16 11:55 ` Robin Holt

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=20120627135155.GA3464@sgi.com \
    --to=holt@sgi.com \
    --cc=akpm@linux-foundation.org \
    --cc=dan.carpenter@oracle.com \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=steiner@sgi.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