From: Milton Miller <miltonm@bga.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
Benjiman Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev list <linuxppc-dev@ozlabs.org>,
lkml <linux-kernel@vger.kernel.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: [PATCH 4/4] hvc_console: comment mb and make it an smp_ one
Date: Thu, 08 Jan 2009 06:14:18 -0600 [thread overview]
Message-ID: <hvc-console-29-3-4@bga.com> (raw)
In-Reply-To: : <hvc-console-29-3@bga.com>
I remember some history on this barrier. There was a race between
open via /dev/console and the tty being fully setup. Its also why
there is a temporary variable and the global is assigned at the end
of the function.
Signed-off-by: Milton Miller <miltonm@bga.com>
Index: work.git/drivers/char/hvc_console.c
===================================================================
--- work.git.orig/drivers/char/hvc_console.c 2009-01-08 04:33:39.000000000 -0600
+++ work.git/drivers/char/hvc_console.c 2009-01-08 04:35:09.000000000 -0600
@@ -875,8 +875,11 @@ static int hvc_init(void)
goto stop_thread;
}
- /* FIXME: This mb() seems completely random. Remove it. */
- mb();
+ /*
+ * Make sure tty is fully registered before allowing it to be
+ * found by hvc_console_device.
+ */
+ smp_mb();
hvc_driver = drv;
return 0;
next prev parent reply other threads:[~2009-01-08 12:15 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-08 5:18 [BUG] hvc_console WARN() on current upstream Benjamin Herrenschmidt
2009-01-08 7:57 ` Christian Borntraeger
2009-01-08 8:42 ` Benjamin Herrenschmidt
2009-01-08 11:11 ` Alan Cox
2009-01-08 12:12 ` [PATCH 0/5] hvc_console updates was " Milton Miller
2009-01-08 12:14 ` Milton Miller [this message]
2009-01-08 12:14 ` [PATCH 3/4] hvc_console: free_irq only if request_irq was successful Milton Miller
2009-01-08 16:50 ` Christian Borntraeger
2009-01-08 12:14 ` [PATCH 1/4] hvc_console: do not set low_latency Milton Miller
2009-01-08 12:36 ` Alan Cox
2009-01-08 13:25 ` Milton Miller
2009-01-13 9:04 ` Christian Borntraeger
2009-01-13 11:28 ` Christian Borntraeger
2009-01-13 11:35 ` Hendrik Brueckner
2009-01-13 16:03 ` Milton Miller
2009-01-13 21:04 ` Benjamin Herrenschmidt
2009-01-15 9:15 ` [PATCH 1/4 v2] hvc_console: remove tty->low_latency Hendrik Brueckner
2009-01-15 9:17 ` Christian Borntraeger
2009-01-08 12:14 ` [PATCH 2/4] hvc_console: use kzalloc Milton Miller
2009-01-08 20:36 ` [BUG] hvc_console WARN() on current upstream Benjamin Herrenschmidt
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