From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Date: Wed, 19 May 2010 13:38:58 +0000 Subject: [PATCH #upstream-fixes] libata: disable ATAPI AN by default Message-Id: <4BF3E9F2.9050608@kernel.org> List-Id: References: <20100517225405.GA19825@cpu18.student.cs> <20100518132519.GA19658@elliptictech.com> <20100518162350.GA29594@elliptictech.com> <4BF2D8E8.1040602@kernel.org> <4BF2DC55.5010209@kernel.org> <20100518192300.GA30821@elliptictech.com> <4BF3E64D.2040003@kernel.org> In-Reply-To: <4BF3E64D.2040003@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jeff Garzik , "linux-ide@vger.kernel.org" Cc: Kay Sievers , Nick Bowler , David Zeuthen , linux-hotplug@vger.kernel.org, stable@kernel.org 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 Cc: stable@kernel.org --- drivers/ata/libata-core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 49cffb6..5abab5d 100644 --- 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 (0f [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 *dev) * 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;