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authorTejun Heo <tj@kernel.org>2010-05-19 15:38:58 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-07-05 11:08:41 -0700
commit90bfd720bcda3a04e22be93b66138a117c0bcf28 (patch)
tree93e54ca684cf1c3457e89423a84d884ee1de2a40 /drivers
parenta9a5c1f8a527bd150ce044b8c9acce1c97c557a4 (diff)
libata: disable ATAPI AN by default
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 <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Nick Bowler <nbowler@elliptictech.com> Cc: David Zeuthen <david@fubar.dk> Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/ata/libata-core.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8afc2740f1dc..512c28190abe 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -157,6 +157,10 @@ 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");
+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");
@@ -2341,7 +2345,8 @@ 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;