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From: "John W. Linville" <linville@tuxdriver.com>
To: Roger Luethi <rl@hellgate.ch>
Cc: Marco Berizzi <pupilla@hotmail.com>, netdev@vger.kernel.org
Subject: Re: via_rhine modules error on 2.6.16 with mii-tool
Date: Thu, 13 Apr 2006 14:26:43 -0400	[thread overview]
Message-ID: <20060413182638.GC25854@tuxdriver.com> (raw)
In-Reply-To: <20060327203946.GA11824@k3.hellgate.ch>

On Mon, Mar 27, 2006 at 10:39:46PM +0200, Roger Luethi wrote:
> On Fri, 24 Mar 2006 16:49:10 +0100, Marco Berizzi wrote:
> > Hello evebody.
> > I get this error on linux vanilla 2.6.16
> > with via_rhine module loaded  when
> > I run mii-tool:
> 
> That was caused by a recent change that replaced an mdelay with msleep.
> 
> netdev_ioctl and friends (ethtool calls, too) are known to grab a spin lock
> before they do much of anything, and they hang onto it until they're done.
> They also call mdio_read/write, which requires millisecond delays on Rhine-I.
> 
> So on Rhine-I with a 2.6.15+ kernel, the driver ends up calling msleep
> while holding a spin lock -- hence the stack dump.
> 
> I wonder if low latency for ancient Rhine-I chips is worth the trouble.

IIRC, the point was that mdelay was getting called in interrupt
context and causing ugly messages to show-up in dmesg.

Would the patch below be sufficient?  Or does the whole patch need
to be reverted?

John

diff --git a/drivers/net/via-rhine.c b/drivers/net/via-rhine.c
index 2418715..e7b4bc3 100644
--- a/drivers/net/via-rhine.c
+++ b/drivers/net/via-rhine.c
@@ -1145,8 +1130,8 @@ static void rhine_disable_linkmon(void _
 	if (quirks & rqRhineI) {
 		iowrite8(0x01, ioaddr + MIIRegAddr);	// MII_BMSR
 
-		/* Do not call from ISR! */
-		msleep(1);
+		/* Can be called from ISR. Evil. */
+		mdelay(1);
 
 		/* 0x80 must be set immediately before turning it off */
 		iowrite8(0x80, ioaddr + MIICmd);
-- 
John W. Linville
linville@tuxdriver.com

       reply	other threads:[~2006-04-13 18:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <BAY103-F401F96F0B06D75E70AF0BFB2DF0@phx.gbl>
     [not found] ` <20060327203946.GA11824@k3.hellgate.ch>
2006-04-13 18:26   ` John W. Linville [this message]
2006-04-13 18:40     ` via_rhine modules error on 2.6.16 with mii-tool Stephen Hemminger
2006-04-13 20:47       ` Roger Luethi
2006-04-13 21:02         ` Stephen Hemminger
2006-04-13 21:36           ` Francois Romieu
2006-04-13 21:55           ` Roger Luethi
2006-04-13 20:31     ` Roger Luethi
2006-05-19 14:41       ` [patch] via-rhine: revert "change mdelay to msleep and remove from ISR path" John W. Linville
2006-05-19 14:51         ` [patch w/o fuzz] " John W. Linville

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