libata: implement libata.force module parameter
This patch implements libata.force module parameter which can
selectively override ATA port, link and device configurations
including cable type, SATA PHY SPD limit, transfer mode and NCQ.
For example, you can say "use 1.5Gbps for all fan-out ports attached
to the second port but allow 3.0Gbps for the PMP device itself, oh,
the device attached to the third fan-out port chokes on NCQ and
shouldn't go over UDMA4" by the following.
libata.force=2:1.5g,2.15:3.0g,2.03:noncq,udma4
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 409ffb9..6036ded 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -61,6 +61,7 @@
extern int libata_fua;
extern int libata_noacpi;
extern int libata_allow_tpm;
+extern void ata_force_cbl(struct ata_port *ap);
extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
u64 block, u32 n_block, unsigned int tf_flags,