libata: allow sata_sil24 to opt-out of tag ordered submission

commit 72dd299d5039a336493993dcc63413cf31d0e662 upstream.

Ronny reports: https://bugzilla.kernel.org/show_bug.cgi?id=87101
    "Since commit 8a4aeec8d "libata/ahci: accommodate tag ordered
    controllers" the access to the harddisk on the first SATA-port is
    failing on its first access. The access to the harddisk on the
    second port is working normal.

    When reverting the above commit, access to both harddisks is working
    fine again."

Maintain tag ordered submission as the default, but allow sata_sil24 to
continue with the old behavior.

Cc: Tejun Heo <tj@kernel.org>
Reported-by: Ronny Hegewald <Ronny.Hegewald@online.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2ddf7368a3af9660bf94f201069c0013eee0a392..5d8fc3dd682aaa771215e7f5d33d175bb52cfe04 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4730,7 +4730,10 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
                return NULL;
 
        for (i = 0, tag = ap->last_tag + 1; i < max_queue; i++, tag++) {
-               tag = tag < max_queue ? tag : 0;
+               if (ap->flags & ATA_FLAG_LOWTAG)
+                       tag = i;
+               else
+                       tag = tag < max_queue ? tag : 0;
 
                /* the last tag is reserved for internal command. */
                if (tag == ATA_TAG_INTERNAL)

diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 1e9140626a8371eae9e846bb2fd9fb3a327136e6..2178022b9b84248b58ff3d53c5cdbc82aa9ee2a0 100644 (file)
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -246,7 +246,7 @@ enum {
        /* host flags */
        SIL24_COMMON_FLAGS      = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA |
                                  ATA_FLAG_NCQ | ATA_FLAG_ACPI_SATA |
-                                 ATA_FLAG_AN | ATA_FLAG_PMP,
+                                 ATA_FLAG_AN | ATA_FLAG_PMP | ATA_FLAG_LOWTAG,
        SIL24_FLAG_PCIX_IRQ_WOC = (1 << 24), /* IRQ loss errata on PCI-X */
 
        IRQ_STAT_4PORTS         = 0xf,

diff --git a/include/linux/libata.h b/include/linux/libata.h
index d773b2143b69d0063da29647062ca8b1ae33970c..42ac6ad8a69a73218d9693580fe0be8c6138692a 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -207,6 +207,7 @@ enum {
        ATA_FLAG_SW_ACTIVITY    = (1 << 22), /* driver supports sw activity
                                              * led */
        ATA_FLAG_NO_DIPM        = (1 << 23), /* host not happy with DIPM */
+       ATA_FLAG_LOWTAG         = (1 << 24), /* host wants lowest available tag */
 
        /* bits 24:31 of ap->flags are reserved for LLD specific flags */