libata: disable a disk via libata.force params

commit b8bd6dc36186fe99afa7b73e9e2d9a98ad5c4865 upstream.

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>
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://unix.stackexchange.com/questions/102648/how-to-tell-linux-kernel-3-0-to-completely-ignore-a-failing-disk
Link: http://askubuntu.com/questions/352836/how-can-i-tell-linux-kernel-to-completely-ignore-a-disk-as-if-it-was-not-even-co
Link: http://superuser.com/questions/599333/how-to-disable-kernel-probing-for-drive
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 96401631523d26787c9e03ef8938bd08bd8c8d9f..1311a48a7367cb9912875d3d04c0ce1b4f266c1e 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1458,6 +1458,8 @@ 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 d18ab9015e3ecf0d0b7a322ebcd63849be68ab57..8cacd1693f030d74e7e838e1ccc7459cb26d85c5 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6507,6 +6507,7 @@ 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;