From e7ecd435692ca9bde9d124be30b3a26e672ea6c2 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 19 May 2010 15:38:58 +0200 Subject: [PATCH] libata: disable ATAPI AN by default 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 Signed-off-by: Jeff Garzik --- 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 c47373f..8959f42 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 (0=0ff [default], 1=on)"); + MODULE_AUTHOR("Jeff Garzik"); MODULE_DESCRIPTION("Library module for ATA devices"); MODULE_LICENSE("GPL"); @@ -2510,7 +2514,8 @@ 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; -- 2.7.4