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| author | Tejun Heo <htejun@gmail.com> | 2007-09-23 08:19:54 +0400 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-10-12 22:55:44 +0400 |
| commit | 31f88384443b3e0d7e2c9d36a96647b7e82edad3 (patch) | |
| tree | 7bd6321d668f86adbf266513b83a75ae8d568772 /drivers/ata/libata-pmp.c | |
| parent | d0df8b5d0fb547a3351c2a4b1ded7f7cde5d713a (diff) | |
| download | linux-31f88384443b3e0d7e2c9d36a96647b7e82edad3.tar.xz | |
libata-pmp: implement qc_defer for command switching PMP support
Implement sata_pmp_qc_defer_cmd_switch() - standard qc_defer for
command switching PMP support.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/libata-pmp.c')
| -rw-r--r-- | drivers/ata/libata-pmp.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c index eeffce636d0c..f6c4b11336e9 100644 --- a/drivers/ata/libata-pmp.c +++ b/drivers/ata/libata-pmp.c @@ -70,6 +70,36 @@ static int sata_pmp_write(struct ata_link *link, int reg, u32 val) } /** + * sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP + * @qc: ATA command in question + * + * A host which has command switching PMP support cannot issue + * commands to multiple links simultaneously. + * + * LOCKING: + * spin_lock_irqsave(host lock) + * + * RETURNS: + * ATA_DEFER_* if deferring is needed, 0 otherwise. + */ +int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc) +{ + struct ata_link *link = qc->dev->link; + struct ata_port *ap = link->ap; + + if (ap->excl_link == NULL || ap->excl_link == link) { + if (ap->nr_active_links == 0 || ata_link_active(link)) { + qc->flags |= ATA_QCFLAG_CLEAR_EXCL; + return ata_std_qc_defer(qc); + } + + ap->excl_link = link; + } + + return ATA_DEFER_PORT; +} + +/** * sata_pmp_read_init_tf - initialize TF for PMP read * @tf: taskfile to initialize * @dev: PMP dev |