[PATCH] libata: kill E.D.D.

E.D.D. has no user in-tree and mostly useless.  Kill it.  For possible
out-of-tree users, add a nice warning message and error handling if
LLDD doesn't report any useable reset mechanism (and thus tries to use
E.D.D.).

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

2 files changed, 13 insertions, 86 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index d279666dcb38..0aff888d9ecd 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1081,9 +1081,8 @@ unsigned int ata_pio_need_iordy(const struct ata_device *adev)
  *
  *      Read ID data from the specified device.  ATA_CMD_ID_ATA is
  *      performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
- *      devices.  This function also takes care of EDD signature
- *      misreporting (to be removed once EDD support is gone) and
- *      issues ATA_CMD_INIT_DEV_PARAMS for pre-ATA4 drives.
+ *      devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
+ *      for pre-ATA4 drives.
  *
  *      LOCKING:
  *      Kernel thread context (may sleep)
@@ -1095,7 +1094,6 @@ static int ata_dev_read_id(struct ata_port *ap, struct ata_device *dev,
                            unsigned int *p_class, int post_reset, u16 **p_id)
 {
         unsigned int class = *p_class;
-        unsigned int using_edd;
         struct ata_taskfile tf;
         unsigned int err_mask = 0;
         u16 *id;
@@ -1104,12 +1102,6 @@ static int ata_dev_read_id(struct ata_port *ap, struct ata_device *dev,
 
         DPRINTK("ENTER, host %u, dev %u\n", ap->id, dev->devno);
 
-        if (ap->ops->probe_reset ||
-            ap->flags & (ATA_FLAG_SRST | ATA_FLAG_SATA_RESET))
-                using_edd = 0;
-        else
-                using_edd = 1;
-
         ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
 
         id = kmalloc(sizeof(id[0]) * ATA_ID_WORDS, GFP_KERNEL);
@@ -1139,32 +1131,9 @@ static int ata_dev_read_id(struct ata_port *ap, struct ata_device *dev,
 
         err_mask = ata_exec_internal(ap, dev, &tf, DMA_FROM_DEVICE,
                                      id, sizeof(id[0]) * ATA_ID_WORDS);
-
         if (err_mask) {
                 rc = -EIO;
                 reason = "I/O error";
-
-                if (err_mask & ~AC_ERR_DEV)
-                        goto err_out;
-
-                /*
-                 * arg!  EDD works for all test cases, but seems to return
-                 * the ATA signature for some ATAPI devices.  Until the
-                 * reason for this is found and fixed, we fix up the mess
-                 * here.  If IDENTIFY DEVICE returns command aborted
-                 * (as ATAPI devices do), then we issue an
-                 * IDENTIFY PACKET DEVICE.
-                 *
-                 * ATA software reset (SRST, the default) does not appear
-                 * to have this problem.
-                 */
-                if ((using_edd) && (class == ATA_DEV_ATA)) {
-                        u8 err = tf.feature;
-                        if (err & ATA_ABORTED) {
-                                class = ATA_DEV_ATAPI;
-                                goto retry;
-                        }
-                }
                 goto err_out;
         }
 
@@ -2005,45 +1974,6 @@ static void ata_bus_post_reset(struct ata_port *ap, unsigned int devmask)
                 ap->ops->dev_select(ap, 0);
 }
 
-/**
- *      ata_bus_edd - Issue EXECUTE DEVICE DIAGNOSTIC command.
- *      @ap: Port to reset and probe
- *
- *      Use the EXECUTE DEVICE DIAGNOSTIC command to reset and
- *      probe the bus.  Not often used these days.
- *
- *      LOCKING:
- *      PCI/etc. bus probe sem.
- *      Obtains host_set lock.
- *
- */
-
-static unsigned int ata_bus_edd(struct ata_port *ap)
-{
-        struct ata_taskfile tf;
-        unsigned long flags;
-
-        /* set up execute-device-diag (bus reset) taskfile */
-        /* also, take interrupts to a known state (disabled) */
-        DPRINTK("execute-device-diag\n");
-        ata_tf_init(ap, &tf, 0);
-        tf.ctl |= ATA_NIEN;
-        tf.command = ATA_CMD_EDD;
-        tf.protocol = ATA_PROT_NODATA;
-
-        /* do bus reset */
-        spin_lock_irqsave(&ap->host_set->lock, flags);
-        ata_tf_to_host(ap, &tf);
-        spin_unlock_irqrestore(&ap->host_set->lock, flags);
-
-        /* spec says at least 2ms.  but who knows with those
-         * crazy ATAPI devices...
-         */
-        msleep(150);
-
-        return ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
-}
-
 static unsigned int ata_bus_softreset(struct ata_port *ap,
                                       unsigned int devmask)
 {
@@ -2116,7 +2046,7 @@ void ata_bus_reset(struct ata_port *ap)
         struct ata_ioports *ioaddr = &ap->ioaddr;
         unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
         u8 err;
-        unsigned int dev0, dev1 = 0, rc = 0, devmask = 0;
+        unsigned int dev0, dev1 = 0, devmask = 0;
 
         DPRINTK("ENTER, host %u, port %u\n", ap->id, ap->port_no);
 
@@ -2139,18 +2069,8 @@ void ata_bus_reset(struct ata_port *ap)
 
         /* issue bus reset */
         if (ap->flags & ATA_FLAG_SRST)
-                rc = ata_bus_softreset(ap, devmask);
-        else if ((ap->flags & ATA_FLAG_SATA_RESET) == 0) {
-                /* set up device control */
-                if (ap->flags & ATA_FLAG_MMIO)
-                        writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
-                else
-                        outb(ap->ctl, ioaddr->ctl_addr);
-                rc = ata_bus_edd(ap);
-        }
-
-        if (rc)
-                goto err_out;
+                if (ata_bus_softreset(ap, devmask))
+                        goto err_out;
 
         /*
          * determine by signature whether we have ATA or ATAPI devices
@@ -4536,6 +4456,14 @@ static struct ata_port * ata_host_add(const struct ata_probe_ent *ent,
         int rc;
 
         DPRINTK("ENTER\n");
+
+        if (!ent->port_ops->probe_reset &&
+            !(ent->host_flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST))) {
+                printk(KERN_ERR "ata%u: no reset mechanism available\n",
+                       port_no);
+                return NULL;
+        }
+
         host = scsi_host_alloc(ent->sht, sizeof(struct ata_port));
         if (!host)
                 return NULL;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 047192253c3a..9fcc061e3adf 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -161,7 +161,6 @@ enum {
         ATA_QCFLAG_EH_SCHEDULED = (1 << 5), /* EH scheduled */
 
         /* various lengths of time */
-        ATA_TMOUT_EDD           = 5 * HZ,       /* heuristic */
         ATA_TMOUT_PIO           = 30 * HZ,
         ATA_TMOUT_BOOT          = 30 * HZ,      /* heuristic */
         ATA_TMOUT_BOOT_QUICK    = 7 * HZ,       /* heuristic */