[PATCH] libata: implement ATA_EHI_SETMODE and ATA_EHI_POST_SETMODE

libata EH used to perform ata_set_mode() iff the EH session performed
reset as indicated by ATA_EHI_DID_RESET.  This is incorrect because
->dev_config() called by revalidation is allowed to modify transfer
mode which ata_set_mode() should take care of.  This patch implements
the following two flags.

* ATA_EHI_SETMODE: set during EH to schedule ata_set_mode().  Both new
  device attachment and revalidation set this flag.

* ATA_EHI_POST_SETMODE: set while the device is revalidated after
  ata_set_mode().  Post-setmode revalidation is different from initial
  configuaration and EH revalidation in that ->dev_config() is not
  allowed tune transfer mode.  LLD can use this flag to determine
  whether it's allowed to tune transfer mode.  Note that POST_SETMODE
  ->dev_config() is guaranteed to be preceded by non-POST_SETMODE
  ->dev_config().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index e294731..5028396 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2158,6 +2158,7 @@ int ata_down_xfermask_limit(struct ata_device *dev, int force_pio0)
 
 static int ata_dev_set_mode(struct ata_device *dev)
 {
+       struct ata_eh_context *ehc = &dev->ap->eh_context;
        unsigned int err_mask;
        int rc;
 
@@ -2172,7 +2173,9 @@ static int ata_dev_set_mode(struct ata_device *dev)
                return -EIO;
        }
 
+       ehc->i.flags |= ATA_EHI_POST_SETMODE;
        rc = ata_dev_revalidate(dev, 0);
+       ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
        if (rc)
                return rc;
 

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 7c44644..4776488 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1653,6 +1653,11 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
 
                        ata_eh_done(ap, dev, ATA_EH_REVALIDATE);
 
+                       /* Configuration may have changed, reconfigure
+                        * transfer mode.
+                        */
+                       ehc->i.flags |= ATA_EHI_SETMODE;
+
                        /* schedule the scsi_rescan_device() here */
                        queue_work(ata_aux_wq, &(ap->scsi_rescan_task));
                } else if (dev->class == ATA_DEV_UNKNOWN &&
@@ -1675,6 +1680,9 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
                        spin_lock_irqsave(ap->lock, flags);
                        ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
                        spin_unlock_irqrestore(ap->lock, flags);
+
+                       /* new device discovered, configure transfer mode */
+                       ehc->i.flags |= ATA_EHI_SETMODE;
                }
        }
 
@@ -1990,13 +1998,14 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
        if (rc)
                goto dev_fail;
 
-       /* configure transfer mode if the port has been reset */
-       if (ehc->i.flags & ATA_EHI_DID_RESET) {
+       /* configure transfer mode if necessary */
+       if (ehc->i.flags & ATA_EHI_SETMODE) {
                rc = ata_set_mode(ap, &dev);
                if (rc) {
                        down_xfermask = 1;
                        goto dev_fail;
                }
+               ehc->i.flags &= ~ATA_EHI_SETMODE;
        }
 
        /* suspend devices */

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9494846..0d0ddea 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -284,6 +284,8 @@ enum {
 
        ATA_EHI_DID_RESET       = (1 << 16), /* already reset this port */
        ATA_EHI_PRINTINFO       = (1 << 17), /* print configuration info */
+       ATA_EHI_SETMODE         = (1 << 18), /* configure transfer mode */
+       ATA_EHI_POST_SETMODE    = (1 << 19), /* revaildating after setmode */
 
        ATA_EHI_RESET_MODIFIER_MASK = ATA_EHI_RESUME_LINK,