Adds AHCI support for the VIA VT8251.
Includes a workaround for a hardware bug which requires a Command List
Override before softreset.
Signed-off-by: Bastiaan Jacques <b.jacques@xxxxxxxxx>
---
I have been informed that VIA have also made a patch available for the
sata_via driver for this chip. Do you think it would be useful to merge
that patch in addition to the AHCI one, or does AHCI support make the
"native" sata_via driver obsolete?
Below is the latest version of the (AHCI) patch, with a small change to
the error handling in ahci_softreset(): test for "if (rc)" just in case
someone decides to change the error return values of ahci_clo().
This patch is against libata-dev.git upstream[1].
[1] 26ec634c31a11a003040e10b4d650495158632fd
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 1b8429c..2fe4850 100644
--- a/drivers/scsi/ahci.c
+++ b/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 }, /* VT8251 */
{ } /* terminate list */
};
@@ -516,9 +532,29 @@ static void ahci_fill_cmd_slot(struct ah
pp->cmd_slot[0].tbl_addr_hi = cpu_to_le32((pp->cmd_tbl_dma >> 16) >> 16);
}
-static int ahci_softreset(struct ata_port *ap, 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, 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);
@@ -547,21 +583,13 @@ 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)) {
- if (!(hpriv->cap & HOST_CAP_CLO)) {
- rc = -EIO;
- reason = "port busy but no CLO";
- goto fail_restart;
- }
-
- tmp = readl(port_mmio + PORT_CMD);
- tmp |= PORT_CMD_CLO;
- writel(tmp, port_mmio + PORT_CMD);
+ rc = ahci_clo(ap);
- tmp = ata_wait_register(port_mmio + PORT_CMD,
- PORT_CMD_CLO, PORT_CMD_CLO, 1, 500);
- if (tmp & PORT_CMD_CLO) {
- rc = -EIO;
- reason = "CLO failed";
+ if (rc == -EOPNOTSUPP) {
+ reason = "port busy but CLO unavailable";
+ goto fail_restart;
+ } else if (rc) {
+ reason = "port busy but CLO failed";
goto fail_restart;
}
}
@@ -672,6 +700,12 @@ 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);
-
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