From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([66.187.233.31]:55887 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758173AbYCSTnm (ORCPT ); Wed, 19 Mar 2008 15:43:42 -0400 Subject: Re: [PATCH] libertas: fix spinlock recursion bug From: Dan Williams To: Holger Schurig Cc: libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, "John W. Linville" In-Reply-To: <200803191524.21866.hs4233@mail.mn-solutions.de> References: <200803191524.21866.hs4233@mail.mn-solutions.de> Content-Type: text/plain Date: Wed, 19 Mar 2008 11:02:46 -0400 Message-Id: <1205938966.26119.37.camel@localhost.localdomain> (sfid-20080319_194519_562531_6C81A9A4) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2008-03-19 at 15:24 +0100, Holger Schurig wrote: > This fixes a bug detected by CONFIG_DEBUG_SPINLOCK: > > if_cs_get_int_status() is only called from lbs_thread(), via > priv->hw_get_int_status. However, lbs_thread() has already taken the > priv->driver_lock. So it's a fault to take the same lock again here. > > Signed-off-by: Holger Schurig Acked-by: Dan Williams > CONFIG_DEBUG_SPINLOCK, > --- > > John, this patch might also go into linux-2.6.25-rcX > > Index: wireless-testing/drivers/net/wireless/libertas/if_cs.c > =================================================================== > --- wireless-testing.orig/drivers/net/wireless/libertas/if_cs.c 2008-03-19 13:46:47.000000000 +0100 > +++ wireless-testing/drivers/net/wireless/libertas/if_cs.c 2008-03-19 13:46:53.000000000 +0100 > @@ -677,9 +677,7 @@ sbi_get_int_status_exit: > > /* Card has a command result for us */ > if (*ireg & IF_CS_C_S_CMD_UPLD_RDY) { > - spin_lock(&priv->driver_lock); > ret = if_cs_receive_cmdres(priv, priv->upld_buf, &priv->upld_len); > - spin_unlock(&priv->driver_lock); > if (ret < 0) > lbs_pr_err("could not receive cmd from card\n"); > }