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VIA VT8251 SATA support

2.6.17 backport Daniel Drake 1 participant 1 message Jul 9, 2006

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I added the PCI ID for the VT8251 IDE controller and since then I've been getting a continuous flow of emails from people who think I might have some clue about the SATA side. I don't even own the hardware, but I have backported the patch for inclusion in the Gentoo kernels now that it has been merged into the 2.6.18 tree. This patch is reported to work with 2.6.17.

NOTE: This is unsupported by me, and unsupported the Linux IDE/SATA developers too. The patch is slightly ugly because it includes a backport of the ata_wait_register() function so the end product is that we have some code using ata_wait_register() and some using whatever the predecessor was.

Hoping for fewer emails about this annoying hardware... ;)
Daniel

From: Bastiaan Jacques <[email protected]>
Date: Mon, 17 Apr 2006 12:17:59 +0000 (+0200)
Subject: [PATCH] ahci: add support for VIA VT8251
X-Git-Tag: v2.6.17-rc3
X-Git-Url: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=bf2af2a2027e52b653882fbca840620e896ae081

[PATCH] ahci: add support for VIA VT8251

Adds AHCI support for the VIA VT8251.

Includes a workaround for a hardware bug which requires a Command List Override before softreset.

---

Backported to 2.6.17 by Daniel Drake <[email protected]> Includes addition of ata_wait_register() function

drivers/scsi/ahci.c +48 -16
Index: linux-2.6.17-gentoo-r1/drivers/scsi/ahci.c
===================================================================
@@ -73,6 +73,7 @@ enum {
 	RX_FIS_D2H_REG		= 0x40,	/* offset of D2H Register FIS data */
 
 	board_ahci		= 0,
+	board_ahci_vt8251	= 1,
 
 	/* global controller registers */
 	HOST_CAP		= 0x00, /* host capabilities */
@@ -153,6 +154,9 @@ enum {
 
 	/* hpriv->flags bits */
 	AHCI_FLAG_MSI		= (1 << 0),
+
+	/* ap->flags bits */
+	AHCI_FLAG_RESET_NEEDS_CLO	= (1 << 24),
 };
 
 struct ahci_cmd_hdr {
@@ -255,6 +259,16 @@ static const struct ata_port_info ahci_p
 		.udma_mask	= 0x7f, /* udma0-6 ; FIXME */
 		.port_ops	= &ahci_ops,
 	},
+	/* board_ahci_vt8251 */
+	{
+		.sht		= &ahci_sht,
+		.host_flags	= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
+				  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
+				  AHCI_FLAG_RESET_NEEDS_CLO,
+		.pio_mask	= 0x1f, /* pio0-4 */
+		.udma_mask	= 0x7f, /* udma0-6 ; FIXME */
+		.port_ops	= &ahci_ops,
+	},
 };
 
 static const struct pci_device_id ahci_pci_tbl[] = {
@@ -296,6 +310,8 @@ static const struct pci_device_id ahci_p
 	  board_ahci }, /* ATI SB600 non-raid */
 	{ PCI_VENDOR_ID_ATI, 0x4381, PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 	  board_ahci }, /* ATI SB600 raid */
+	{ PCI_VENDOR_ID_VIA, 0x3349, PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+	  board_ahci_vt8251 }, /* VIA VT8251 */
 	{ }	/* terminate list */
 };
 
@@ -534,9 +550,29 @@ static int ahci_poll_register(void __iom
 	return -1;
 }
 
-static int ahci_softreset(struct ata_port *ap, int verbose, unsigned int *class)
+static int ahci_clo(struct ata_port *ap)
 {
+	void __iomem *port_mmio = (void __iomem *) ap->ioaddr.cmd_addr;
 	struct ahci_host_priv *hpriv = ap->host_set->private_data;
+	u32 tmp;
+
+	if (!(hpriv->cap & HOST_CAP_CLO))
+		return -EOPNOTSUPP;
+
+	tmp = readl(port_mmio + PORT_CMD);
+	tmp |= PORT_CMD_CLO;
+	writel(tmp, port_mmio + PORT_CMD);
+
+	tmp = ata_wait_register(port_mmio + PORT_CMD,
+				PORT_CMD_CLO, PORT_CMD_CLO, 1, 500);
+	if (tmp & PORT_CMD_CLO)
+		return -EIO;
+
+	return 0;
+}
+
+static int ahci_softreset(struct ata_port *ap, int verbose, unsigned int *class)
+{
 	struct ahci_port_priv *pp = ap->private_data;
 	void __iomem *mmio = ap->host_set->mmio_base;
 	void __iomem *port_mmio = ahci_port_base(mmio, ap->port_no);
@@ -558,23 +594,13 @@ static int ahci_softreset(struct ata_por
 	/* check BUSY/DRQ, perform Command List Override if necessary */
 	ahci_tf_read(ap, &tf);
 	if (tf.command & (ATA_BUSY | ATA_DRQ)) {
-		u32 tmp;
+		rc = ahci_clo(ap);
 
-		if (!(hpriv->cap & HOST_CAP_CLO)) {
-			rc = -EIO;
-			reason = "port busy but no CLO";
+		if (rc == -EOPNOTSUPP) {
+			reason = "port busy but CLO unavailable";
 			goto fail_restart;
-		}
-
-		tmp = readl(port_mmio + PORT_CMD);
-		tmp |= PORT_CMD_CLO;
-		writel(tmp, port_mmio + PORT_CMD);
-		readl(port_mmio + PORT_CMD); /* flush */
-
-		if (ahci_poll_register(port_mmio + PORT_CMD, PORT_CMD_CLO, 0x0,
-				       1, 500)) {
-			rc = -EIO;
-			reason = "CLO failed";
+		} else if (rc) {
+			reason = "port busy but CLO failed";
 			goto fail_restart;
 		}
 	}
@@ -688,6 +714,12 @@ static void ahci_postreset(struct ata_po
 
 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);
drivers/scsi/libata-core.c +47 -0

59 lines not on this page · raw message

include/linux/libata.h +3 -0
Index: linux-2.6.17-gentoo-r1/include/linux/libata.h
===================================================================
@@ -537,6 +537,9 @@ extern unsigned int ata_busy_sleep(struc
 				   unsigned long timeout);
 extern void ata_port_queue_task(struct ata_port *ap, void (*fn)(void *),
 				void *data, unsigned long delay);
+extern u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
+			     unsigned long interval_msec,
+			     unsigned long timeout_msec);
 
 /*
  * Default driver ops implementations