[PATCH v2] libata: disable a disk via libata.force params

["Robin H. Johnson" <robbat2@gentoo.org>]

A user on StackExchange had a failing SSD that's soldered directly onto
the motherboard of his system. The BIOS does not give any option to
disable it at all, so he can't just hide it from the OS via the BIOS.

The old IDE layer had hdX=noprobe override for situations like this, but
that was never ported to the libata layer.

This patch implements a disable flag for libata.force.
Example use:
libata.force=2.0:disable

[v2 of the patch, removed the nodisable flag per Tejun Heo]

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
X-URL: http://unix.stackexchange.com/questions/102648/how-to-tell-linux-kernel-3-0-to-completely-ignore-a-failing-disk
X-URL: http://askubuntu.com/questions/352836/how-can-i-tell-linux-kernel-to-completely-ignore-a-disk-as-if-it-was-not-even-co
X-URL: http://superuser.com/questions/599333/how-to-disable-kernel-probing-for-drive
---
 Documentation/kernel-parameters.txt | 2 ++
 drivers/ata/libata-core.c           | 1 +
 2 files changed, 3 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 50680a5..b9e9bd8 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1529,6 +1529,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 			* atapi_dmadir: Enable ATAPI DMADIR bridge support
 
+			* disable: Disable this device.
+
 			If there are multiple matching configurations changing
 			the same attribute, the last one is used.
 
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 75b9367..70529b8 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6519,6 +6519,7 @@ static int __init ata_parse_force_one(char **cur,
 		{ "norst",	.lflags		= ATA_LFLAG_NO_HRST | ATA_LFLAG_NO_SRST },
 		{ "rstonce",	.lflags		= ATA_LFLAG_RST_ONCE },
 		{ "atapi_dmadir", .horkage_on	= ATA_HORKAGE_ATAPI_DMADIR },
+		{ "disable",	.horkage_on	= ATA_HORKAGE_DISABLE },
 	};
 	char *start = *cur, *p = *cur;
 	char *id, *val, *endp;
-- 
1.8.4.3