libata: Implement ATA_FLAG_NO_DIPM and apply it to mcp65

NVIDIA mcp65 familiy of controllers cause command timeouts when DIPM
is used.  Implement ATA_FLAG_NO_DIPM and apply it.

This problem was reported by Stefan Bader in the following thread.

 http://thread.gmane.org/gmane.linux.ide/48841

stable: applicable to 2.6.37 and 38.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 39d829c..cbd38e1 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -150,7 +150,7 @@ static const struct ata_port_info ahci_port_info[] = {
        {
                AHCI_HFLAGS     (AHCI_HFLAG_NO_FPDMA_AA | AHCI_HFLAG_NO_PMP |
                                 AHCI_HFLAG_YES_NCQ),
-               .flags          = AHCI_FLAG_COMMON,
+               .flags          = AHCI_FLAG_COMMON | ATA_FLAG_NO_DIPM,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &ahci_ops,

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 88cd22f..f26f2fe 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3316,6 +3316,7 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
        struct ata_eh_context *ehc = &link->eh_context;
        struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL;
        enum ata_lpm_policy old_policy = link->lpm_policy;
+       bool no_dipm = ap->flags & ATA_FLAG_NO_DIPM;
        unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM;
        unsigned int err_mask;
        int rc;
@@ -3332,7 +3333,7 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
         */
        ata_for_each_dev(dev, link, ENABLED) {
                bool hipm = ata_id_has_hipm(dev->id);
-               bool dipm = ata_id_has_dipm(dev->id);
+               bool dipm = ata_id_has_dipm(dev->id) && !no_dipm;
 
                /* find the first enabled and LPM enabled devices */
                if (!link_dev)
@@ -3389,7 +3390,8 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 
        /* host config updated, enable DIPM if transitioning to MIN_POWER */
        ata_for_each_dev(dev, link, ENABLED) {
-               if (policy == ATA_LPM_MIN_POWER && ata_id_has_dipm(dev->id)) {
+               if (policy == ATA_LPM_MIN_POWER && !no_dipm &&
+                   ata_id_has_dipm(dev->id)) {
                        err_mask = ata_dev_set_feature(dev,
                                        SETFEATURES_SATA_ENABLE, SATA_DIPM);
                        if (err_mask && err_mask != AC_ERR_DEV) {

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3b4d223..04f32a3 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -196,6 +196,7 @@ enum {
                                              * management */
        ATA_FLAG_SW_ACTIVITY    = (1 << 22), /* driver supports sw activity
                                              * led */
+       ATA_FLAG_NO_DIPM        = (1 << 23), /* host not happy with DIPM */
 
        /* bits 24:31 of ap->flags are reserved for LLD specific flags */