Merge remote-tracking branch 'lsk/v3.10/topic/configs' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / drivers / ata / libata-core.c

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8b8cbe9bcb92592ac9c77337786d8fcb26dd0f06..9cf616b5210bcb7b866284caed4f66fa52971a4b 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4765,21 +4765,26 @@ 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;
 }