Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932816Ab1CYX6p (ORCPT ); Fri, 25 Mar 2011 19:58:45 -0400 Received: from kroah.org ([198.145.64.141]:48961 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933060Ab1CYX6a (ORCPT ); Fri, 25 Mar 2011 19:58:30 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Mar 25 16:56:38 2011 Message-Id: <20110325235638.875516896@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 25 Mar 2011 16:56:00 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Stuart Hayes , Doug Warzecha , Chuck Ebbert , Jiri Kosina Subject: [23/23] dcdbas: force SMI to happen when expected References: <20110325235537.660072281@clark.kroah.org> Content-Disposition: inline; filename=dcdbas-force-smi-to-happen-when-expected.patch In-Reply-To: <20110325235654.GA24416@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1462 Lines: 41 From: Stuart Hayes commit dd65c736d1b5312c80c88a64bf521db4959eded5 upstream. The dcdbas driver can do an I/O write to cause a SMI to occur. The SMI handler looks at certain registers and memory locations, so the SMI needs to happen immediately. On some systems I/O writes are posted, though, causing the SMI to happen well after the "outb" occurred, which causes random failures. Following the "outb" with an "inb" forces the write to go through even if it is posted. Signed-off-by: Stuart Hayes Acked-by: Doug Warzecha Cc: Chuck Ebbert Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/dcdbas.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -267,8 +267,10 @@ int dcdbas_smi_request(struct smi_cmd *s } /* generate SMI */ + /* inb to force posted write through and make SMI happen now */ asm volatile ( - "outb %b0,%w1" + "outb %b0,%w1\n" + "inb %w1" : /* no output args */ : "a" (smi_cmd->command_code), "d" (smi_cmd->command_address), -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/