---

yaml --- r: 192592 b: refs/heads/master c: 96d6030 h: refs/heads/master v: v3
git-mirror · May 14, 2010 · bc18a46 · bc18a46
1 parent 70960b1
commit bc18a46
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1c2a49f61785ebbcbfb481a2aab659020f0457f7
+refs/heads/master: 96d60303fd3336893a93565d58c4f1805a327061
diff --git a/trunk/drivers/ata/libahci.c b/trunk/drivers/ata/libahci.c
@@ -437,11 +437,29 @@ static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 	return -EINVAL;
 }
 
+static int ahci_is_device_present(void __iomem *port_mmio)
+{
+	u8 status = readl(port_mmio + PORT_TFDATA) & 0xff;
+
+	/* Make sure PxTFD.STS.BSY and PxTFD.STS.DRQ are 0 */
+	if (status & (ATA_BUSY | ATA_DRQ))
+		return 0;
+
+	/* Make sure PxSSTS.DET is 3h */
+	status = readl(port_mmio + PORT_SCR_STAT) & 0xf;
+	if (status != 3)
+		return 0;
+	return 1;
+}
+
 void ahci_start_engine(struct ata_port *ap)
 {
 	void __iomem *port_mmio = ahci_port_base(ap);
 	u32 tmp;
 
+	if (!ahci_is_device_present(port_mmio))
+		return;
+
 	/* start DMA */
 	tmp = readl(port_mmio + PORT_CMD);
 	tmp |= PORT_CMD_START;