Return-path: Received: from static-ip-62-75-166-246.inaddr.intergenia.de ([62.75.166.246]:35987 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751519AbXE1O4N (ORCPT ); Mon, 28 May 2007 10:56:13 -0400 From: Michael Buesch To: Maximilian Engelhardt , Gary Zambrano Subject: Re: b44: regression in 2.6.22 (resend) Date: Mon, 28 May 2007 16:55:14 +0200 Cc: "linux-kernel" , "linux-wireless" , Stephen Hemminger , Arnaldo Carvalho de Melo , Jeff Garzik , netdev@vger.kernel.org, Andrew Morton References: <20070525172431.60affaca@freepuppy> <200705281249.56106.mb@bu3sch.de> <200705281612.15649.maxi@daemonizer.de> In-Reply-To: <200705281612.15649.maxi@daemonizer.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Message-Id: <200705281655.15105.mb@bu3sch.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Monday 28 May 2007 16:12:12 Maximilian Engelhardt wrote: > On Monday 28 May 2007, Michael Buesch wrote: > > Can you also test the following patch? > > I think there's a bug in b44 that is doesn't properly discard > > shared IRQs, so it might possibly generate a NAPI storm, dunno. > > Worth a try. > > > > Index: linux-2.6.22-rc3/drivers/net/b44.c > > =================================================================== > > --- linux-2.6.22-rc3.orig/drivers/net/b44.c 2007-05-27 23:01:44.000000000 > > +0200 +++ linux-2.6.22-rc3/drivers/net/b44.c 2007-05-28 12:48:27.000000000 > > +0200 @@ -911,6 +911,8 @@ static irqreturn_t b44_interrupt(int irq > > spin_lock(&bp->lock); > > > > istat = br32(bp, B44_ISTAT); > > + if (istat == 0xFFFFFFFF) > > + goto out; /* Shared IRQ not for us */ > > imask = br32(bp, B44_IMASK); > > > > /* The interrupt mask register controls which interrupt bits > > @@ -942,6 +944,7 @@ irq_ack: > > bw32(bp, B44_ISTAT, istat); > > br32(bp, B44_ISTAT); > > } > > +out: > > spin_unlock(&bp->lock); > > return IRQ_RETVAL(handled); > > } > > I did try this patch on a affected kernel, but I didn't notice any big > difference. Perhaps the kernel is a bit less slow during the test, but It's > hard to tell. Ok, but anyway. I think this is a bug and needs to be fixed this way. Gary? -- Greetings Michael.