From: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] plip: replace spin_lock_irq with spin_lock_irqsave in irq context
Date: Tue, 1 Apr 2008 01:22:45 +0200 (CEST) [thread overview]
Message-ID: <Pine.LNX.4.64.0804010113040.29068@artax.karlin.mff.cuni.cz> (raw)
Hi
Plip uses spin_lock_irq/spin_unlock_irq in its IRQ handler (called from
parport IRQ handler), the latter enables interrupts without parport
subsystem IRQ handler expecting it.
The bug can be seen if you compile kernel with lock dependency checking
and use plip --- it produces a warning.
This patch changes it to spin_lock_irqsave/spin_lock_irqrestore, so that
it doesn't enable interrupts when already disabled.
Mikulas
--- linux-2.6.24.4/drivers/net/plip.c_ 2008-03-31 23:47:27.000000000 +0200
+++ linux-2.6.24.4/drivers/net/plip.c 2008-03-31 23:48:06.000000000 +0200
@@ -903,17 +903,18 @@ plip_interrupt(void *dev_id)
struct net_local *nl;
struct plip_local *rcv;
unsigned char c0;
+ unsigned long flags;
nl = netdev_priv(dev);
rcv = &nl->rcv_data;
- spin_lock_irq (&nl->lock);
+ spin_lock_irqsave (&nl->lock, flags);
c0 = read_status(dev);
if ((c0 & 0xf8) != 0xc0) {
if ((dev->irq != -1) && (net_debug > 1))
printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
- spin_unlock_irq (&nl->lock);
+ spin_unlock_irqrestore (&nl->lock, flags);
return;
}
@@ -942,7 +943,7 @@ plip_interrupt(void *dev_id)
break;
}
- spin_unlock_irq(&nl->lock);
+ spin_unlock_irqrestore(&nl->lock, flags);
}
static int
reply other threads:[~2008-03-31 23:22 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=Pine.LNX.4.64.0804010113040.29068@artax.karlin.mff.cuni.cz \
--to=mikulas@artax.karlin.mff.cuni.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.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).