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: Zefan Li <lizefan@huawei.com>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 6b922365d5e9a3e63875f42fc70afe9fd61c1dc6..adaf994abb79ca9918de0cf5d8ba81a90f9f915c 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4712,7 +4712,10 @@ 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 e7e610aa9a7a4c6a9321671eec2002badadb17c0..cb68aa3f72a6c51e14bf702cd0599bd0183fcae6 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 dd16deb27dd8ea418b421a000b53ddf7ac907394..764cd54dfea79ac906a8e3ee2e28dc49d11f45bc 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 */