libata-acpi: implement _GTF command filtering
Implement _GTF command filtering which can be controlled by
libata.acpi_filter kernel parameter. Currently SETXFER and LOCK
commands are filtered.
libata configures transfer mode by itself and _GTF SETXFER commands
can potentially disrupt device configuration. _GTM/_STM mechanism
can't handle hotplugging too well and when _GTF is executed,
controller is in PIO0 rather than the mode _STM configured.
Note that detecting SET MAX LOCK requires looking at the previous
command. This adds a bit to code complexity.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
1 file changed