[PATCH] ahci: convert to new probing mechanism and add hotplug support

Convert to new probing mechanism and add hotplug support by enabling
PORT_IRQ_PHYRDY, marking ehi for hotplug and scheduling EH on
CONNECT/PHYRDY interrupts.

Unfortunately, ahci cannot reliably wait for the first D2H FIS after
hotplug.  It sometimes succeeds but times out more often than not, so
ATA_FLAG_SKIP_D2H_BSY is used.

This patch also fixes ahci_hardreset() such that D2H Register FIS RX
area is cleared before issuing COMRESET.  Without this,
ata_busy_sleep() after COMRESET might prematually finish if the
previous TF contains DRDY && !BSY.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 27 insertions, 20 deletions

diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 60f455bf3696..e261b37c2e48 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -136,6 +136,7 @@ enum {
         PORT_IRQ_FREEZE         = PORT_IRQ_HBUS_ERR |
                                   PORT_IRQ_IF_ERR |
                                   PORT_IRQ_CONNECT |
+                                  PORT_IRQ_PHYRDY |
                                   PORT_IRQ_UNK_FIS,
         PORT_IRQ_ERROR          = PORT_IRQ_FREEZE |
                                   PORT_IRQ_TF_ERR |
@@ -200,7 +201,6 @@ static void ahci_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
 static int ahci_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
 static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc);
 static irqreturn_t ahci_interrupt (int irq, void *dev_instance, struct pt_regs *regs);
-static int ahci_probe_reset(struct ata_port *ap, unsigned int *classes);
 static void ahci_irq_clear(struct ata_port *ap);
 static int ahci_port_start(struct ata_port *ap);
 static void ahci_port_stop(struct ata_port *ap);
@@ -241,8 +241,6 @@ static const struct ata_port_operations ahci_ops = {
 
         .tf_read                = ahci_tf_read,
 
-        .probe_reset            = ahci_probe_reset,
-
         .qc_prep                = ahci_qc_prep,
         .qc_issue               = ahci_qc_issue,
 
@@ -267,7 +265,8 @@ static const struct ata_port_info ahci_port_info[] = {
         {
                 .sht            = &ahci_sht,
                 .host_flags     = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
-                                  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA,
+                                  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
+                                  ATA_FLAG_SKIP_D2H_BSY,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = 0x7f, /* udma0-6 ; FIXME */
                 .port_ops       = &ahci_ops,
@@ -277,6 +276,7 @@ static const struct ata_port_info ahci_port_info[] = {
                 .sht            = &ahci_sht,
                 .host_flags     = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
                                   ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
+                                  ATA_FLAG_SKIP_D2H_BSY |
                                   AHCI_FLAG_RESET_NEEDS_CLO,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = 0x7f, /* udma0-6 ; FIXME */
@@ -569,6 +569,17 @@ static int ahci_clo(struct ata_port *ap)
         return 0;
 }
 
+static int ahci_prereset(struct ata_port *ap)
+{
+        if ((ap->flags & AHCI_FLAG_RESET_NEEDS_CLO) &&
+            (ata_busy_wait(ap, ATA_BUSY, 1000) & ATA_BUSY)) {
+                /* ATA_BUSY hasn't cleared, so send a CLO */
+                ahci_clo(ap);
+        }
+
+        return ata_std_prereset(ap);
+}
+
 static int ahci_softreset(struct ata_port *ap, unsigned int *class)
 {
         struct ahci_port_priv *pp = ap->private_data;
@@ -678,12 +689,22 @@ static int ahci_softreset(struct ata_port *ap, unsigned int *class)
 
 static int ahci_hardreset(struct ata_port *ap, unsigned int *class)
 {
+        struct ahci_port_priv *pp = ap->private_data;
+        u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
+        struct ata_taskfile tf;
         int rc;
 
         DPRINTK("ENTER\n");
 
         ahci_stop_engine(ap);
+
+        /* clear D2H reception area to properly wait for D2H FIS */
+        ata_tf_init(ap->device, &tf);
+        tf.command = 0xff;
+        ata_tf_to_fis(&tf, d2h_fis, 0);
+
         rc = sata_std_hardreset(ap, class);
+
         ahci_start_engine(ap);
 
         if (rc == 0 && ata_port_online(ap))
@@ -714,19 +735,6 @@ static void ahci_postreset(struct ata_port *ap, unsigned int *class)
         }
 }
 
-static int ahci_probe_reset(struct ata_port *ap, unsigned int *classes)
-{
-        if ((ap->flags & AHCI_FLAG_RESET_NEEDS_CLO) &&
-            (ata_busy_wait(ap, ATA_BUSY, 1000) & ATA_BUSY)) {
-                /* ATA_BUSY hasn't cleared, so send a CLO */
-                ahci_clo(ap);
-        }
-
-        return ata_drive_probe_reset(ap, ata_std_probeinit,
-                                     ahci_softreset, ahci_hardreset,
-                                     ahci_postreset, classes);
-}
-
 static u8 ahci_check_status(struct ata_port *ap)
 {
         void __iomem *mmio = (void __iomem *) ap->ioaddr.cmd_addr;
@@ -839,8 +847,7 @@ static void ahci_error_intr(struct ata_port *ap, u32 irq_stat)
         }
 
         if (irq_stat & (PORT_IRQ_CONNECT | PORT_IRQ_PHYRDY)) {
-                err_mask |= AC_ERR_ATA_BUS;
-                action |= ATA_EH_SOFTRESET;
+                ata_ehi_hotplugged(ehi);
                 ata_ehi_push_desc(ehi, ", %s", irq_stat & PORT_IRQ_CONNECT ?
                         "connection status changed" : "PHY RDY changed");
         }
@@ -1027,7 +1034,7 @@ static void ahci_error_handler(struct ata_port *ap)
         }
 
         /* perform recovery */
-        ata_do_eh(ap, ata_std_prereset, ahci_softreset, ahci_hardreset,
+        ata_do_eh(ap, ahci_prereset, ahci_softreset, ahci_hardreset,
                   ahci_postreset);
 }