diff options
| -rw-r--r-- | drivers/ata/libata-core.c | 21 | ||||
| -rw-r--r-- | include/linux/libata.h | 1 |
2 files changed, 14 insertions, 8 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index f2a6020366e1..73c5d0410d47 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4794,21 +4794,26 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words) static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap) { struct ata_queued_cmd *qc = NULL; - unsigned int i; + unsigned int i, tag; /* no command while frozen */ if (unlikely(ap->pflags & ATA_PFLAG_FROZEN)) return NULL; - /* the last tag is reserved for internal command. */ - for (i = 0; i < ATA_MAX_QUEUE - 1; i++) - if (!test_and_set_bit(i, &ap->qc_allocated)) { - qc = __ata_qc_from_tag(ap, i); + for (i = 0; i < ATA_MAX_QUEUE; i++) { + tag = (i + ap->last_tag + 1) % ATA_MAX_QUEUE; + + /* the last tag is reserved for internal command. */ + if (tag == ATA_TAG_INTERNAL) + continue; + + if (!test_and_set_bit(tag, &ap->qc_allocated)) { + qc = __ata_qc_from_tag(ap, tag); + qc->tag = tag; + ap->last_tag = tag; break; } - - if (qc) - qc->tag = i; + } return qc; } diff --git a/include/linux/libata.h b/include/linux/libata.h index 1de36be64df4..5ab4e3a76721 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -822,6 +822,7 @@ struct ata_port { unsigned long qc_allocated; unsigned int qc_active; int nr_active_links; /* #links with active qcs */ + unsigned int last_tag; /* track next tag hw expects */ struct ata_link link; /* host default link */ struct ata_link *slave_link; /* see ata_slave_link_init() */ |