From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758909Ab0GAVNZ (ORCPT ); Thu, 1 Jul 2010 17:13:25 -0400 Received: from kroah.org ([198.145.64.141]:33713 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758820Ab0GAVMt (ORCPT ); Thu, 1 Jul 2010 17:12:49 -0400 X-Mailbox-Line: From gregkh@clark.site Thu Jul 1 10:42:47 2010 Message-Id: <20100701174247.281384439@clark.site> User-Agent: quilt/0.48-10.1 Date: Thu, 01 Jul 2010 10:41:40 -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, Tejun Heo , Kay Sievers , Nick Bowler , David Zeuthen , Jeff Garzik Subject: [010/200] libata: disable ATAPI AN by default In-Reply-To: <20100701175201.GA2149@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.34-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tejun Heo commit e7ecd435692ca9bde9d124be30b3a26e672ea6c2 upstream. There are ATAPI devices which raise AN when hit by commands issued by open(). This leads to infinite loop of AN -> MEDIA_CHANGE uevent -> udev open() to check media -> AN. Both ACS and SerialATA standards don't define in which case ATAPI devices are supposed to raise or not raise AN. They both list media insertion event as a possible use case for ATAPI ANs but there is no clear description of what constitutes such events. As such, it seems a bit too naive to export ANs directly to userland as MEDIA_CHANGE events without further verification (which should behave similarly to windows as it apparently is the only thing that some hardware vendors are testing against). This patch adds libata.atapi_an module parameter and disables ATAPI AN by default for now. Signed-off-by: Tejun Heo Cc: Kay Sievers Cc: Nick Bowler Cc: David Zeuthen Signed-off-by: Jeff Garzik Signed-off-by: Greg Kroah-Hartman --- drivers/ata/libata-core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -160,6 +160,10 @@ int libata_allow_tpm = 0; module_param_named(allow_tpm, libata_allow_tpm, int, 0444); MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands (0=off [default], 1=on)"); +static int atapi_an; +module_param(atapi_an, int, 0444); +MODULE_PARM_DESC(atapi_an, "Enable ATAPI AN media presence notification (0=0ff [default], 1=on)"); + MODULE_AUTHOR("Jeff Garzik"); MODULE_DESCRIPTION("Library module for ATA devices"); MODULE_LICENSE("GPL"); @@ -2572,7 +2576,8 @@ int ata_dev_configure(struct ata_device * to enable ATAPI AN to discern between PHY status * changed notifications and ATAPI ANs. */ - if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) && + if (atapi_an && + (ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) && (!sata_pmp_attached(ap) || sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) { unsigned int err_mask;