[PATCH] sil24: use SRST for phy_reset

There seems to be no way to obtain device signature from sil24 after
SATA phy reset and SRST is needed anyway for later port multiplier
suppport.  This patch converts sil24_phy_reset to use SRST instaed.
Signed-off-by: Tejun Heo <htejun@gmail.com>

--

Jeff, I didn't remove the 10ms sleep just to be on the safe side.  I
think we can live with 10ms sleep on SRST.
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/scsi/sata_sil24.c

@@ -333,7 +333,7 @@ static struct ata_port_info sil24_port_info[] = {
 	{
 		.sht		= &sil24_sht,
 		.host_flags	= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
-				  ATA_FLAG_SATA_RESET | ATA_FLAG_MMIO |
+				  ATA_FLAG_SRST | ATA_FLAG_MMIO |
 				  ATA_FLAG_PIO_DMA | SIL24_NPORTS2FLAG(4),
 		.pio_mask	= 0x1f,			/* pio0-4 */
 		.mwdma_mask	= 0x07,			/* mwdma0-2 */
@@ -344,7 +344,7 @@ static struct ata_port_info sil24_port_info[] = {
 	{
 		.sht		= &sil24_sht,
 		.host_flags	= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
-				  ATA_FLAG_SATA_RESET | ATA_FLAG_MMIO |
+				  ATA_FLAG_SRST | ATA_FLAG_MMIO |
 				  ATA_FLAG_PIO_DMA | SIL24_NPORTS2FLAG(2),
 		.pio_mask	= 0x1f,			/* pio0-4 */
 		.mwdma_mask	= 0x07,			/* mwdma0-2 */
@@ -355,7 +355,7 @@ static struct ata_port_info sil24_port_info[] = {
 	{
 		.sht		= &sil24_sht,
 		.host_flags	= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
-				  ATA_FLAG_SATA_RESET | ATA_FLAG_MMIO |
+				  ATA_FLAG_SRST | ATA_FLAG_MMIO |
 				  ATA_FLAG_PIO_DMA | SIL24_NPORTS2FLAG(1),
 		.pio_mask	= 0x1f,			/* pio0-4 */
 		.mwdma_mask	= 0x07,			/* mwdma0-2 */
@@ -415,16 +415,72 @@ static void sil24_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
 	*tf = pp->tf;
 }
 
-static void sil24_phy_reset(struct ata_port *ap)
+static int sil24_issue_SRST(struct ata_port *ap)
 {
-	__sata_phy_reset(ap);
+	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
+	struct sil24_port_priv *pp = ap->private_data;
+	struct sil24_prb *prb = &pp->cmd_block[0].prb;
+	dma_addr_t paddr = pp->cmd_block_dma;
+	u32 irq_enable, irq_stat;
+	int cnt;
+
+	/* temporarily turn off IRQs during SRST */
+	irq_enable = readl(port + PORT_IRQ_ENABLE_SET);
+	writel(irq_enable, port + PORT_IRQ_ENABLE_CLR);
+
 	/*
-	 * No ATAPI yet.  Just unconditionally indicate ATA device.
-	 * If ATAPI device is attached, it will fail ATA_CMD_ID_ATA
-	 * and libata core will ignore the device.
+	 * XXX: Not sure whether the following sleep is needed or not.
+	 * The original driver had it.  So....
 	 */
-	if (!(ap->flags & ATA_FLAG_PORT_DISABLED))
-		ap->device[0].class = ATA_DEV_ATA;
+	msleep(10);
+
+	prb->ctrl = PRB_CTRL_SRST;
+	prb->fis[1] = 0; /* no PM yet */
+
+	writel((u32)paddr, port + PORT_CMD_ACTIVATE);
+
+	for (cnt = 0; cnt < 100; cnt++) {
+		irq_stat = readl(port + PORT_IRQ_STAT);
+		writel(irq_stat, port + PORT_IRQ_STAT);		/* clear irq */
+
+		irq_stat >>= PORT_IRQ_RAW_SHIFT;
+		if (irq_stat & (PORT_IRQ_COMPLETE | PORT_IRQ_ERROR))
+			break;
+
+		msleep(1);
+	}
+
+	/* restore IRQs */
+	writel(irq_enable, port + PORT_IRQ_ENABLE_SET);
+
+	if (!(irq_stat & PORT_IRQ_COMPLETE))
+		return -1;
+
+	/* update TF */
+	sil24_update_tf(ap);
+	return 0;
+}
+
+static void sil24_phy_reset(struct ata_port *ap)
+{
+	struct sil24_port_priv *pp = ap->private_data;
+
+	__sata_phy_reset(ap);
+	if (ap->flags & ATA_FLAG_PORT_DISABLED)
+		return;
+
+	if (sil24_issue_SRST(ap) < 0) {
+		printk(KERN_ERR DRV_NAME
+		       " ata%u: SRST failed, disabling port\n", ap->id);
+		ap->ops->port_disable(ap);
+		return;
+	}
+
+	ap->device->class = ata_dev_classify(&pp->tf);
+
+	/* No ATAPI yet */
+	if (ap->device->class == ATA_DEV_ATAPI)
+		ap->ops->port_disable(ap);
 }
 
 static inline void sil24_fill_sg(struct ata_queued_cmd *qc,