This patch adds AHCI support for the VIA VT8251 chipset. The patch does so by: 1) Adding the PCI device ID. 2) Adding a workaround in ahci_probe_reset() for a VIA hardware bug. Signed-off-by: Bastiaan Jacques <b.jacques@xxxxxxxxx> --- The patch is based upon the patch[1] provided by VIA. With the softreset and probing work that has been merged, this patch has become much simpler. I am happy to report that without the workaround in ahci_probe_reset(), the chipset works quite well; both my SATA drives are recognised. However, softreset does not work (but hardreset does), and ata_std_probeinit delays, for my primary SATA drive/port, due to the "busy" bug. A Command List Override will unbusy the drive/port. Since the CLO sequence also appears in ahci_softreset(), I have moved that code into a new ahci_clo() function. This patch is against 2.6.17-rc1 (and -mm2). This patch has only been tested by yours truly. Whilst I am waiting for feedback from other people, I am sending this patch to solicit comments. NOTE: My email client cuts off some lines (of context) in my patch because they are longer than 78 characters. Therefore, I am making the patch available from my web server [2], as well. Bastiaan [1] http://lkml.org/lkml/2005/12/11/204 [2] http://mirrors.pagefault.net/linux-via-ahci-latest.patch --- drivers/scsi/ahci.c.orig 2006-04-11 18:58:32.000000000 +0200 +++ drivers/scsi/ahci.c 2006-04-11 12:44:41.000000000 +0200 @@ -297,6 +297,8 @@ 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 */ { } /* terminate list */ }; @@ -535,6 +537,17 @@ return -1; } +static void ahci_clo(struct ata_port *ap) +{ + void __iomem *port_mmio = (void __iomem *) ap->ioaddr.cmd_addr; + u32 tmp; + + tmp = readl(port_mmio + PORT_CMD); + tmp |= PORT_CMD_CLO; + writel(tmp, port_mmio + PORT_CMD); + readl(port_mmio + PORT_CMD); /* flush */ +} + static int ahci_softreset(struct ata_port *ap, int verbose, unsigned int *class) { struct ahci_host_priv *hpriv = ap->host_set->private_data; @@ -565,7 +578,6 @@ /* check BUSY/DRQ, perform Command List Override if necessary */ ahci_tf_read(ap, &tf); if (tf.command & (ATA_BUSY | ATA_DRQ)) { - u32 tmp; if (!(hpriv->cap & HOST_CAP_CLO)) { rc = -EIO; @@ -573,10 +585,7 @@ 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 */ + ahci_clo(ap); if (ahci_poll_register(port_mmio + PORT_CMD, PORT_CMD_CLO, 0x0, 1, 500)) { @@ -695,6 +704,16 @@ static int ahci_probe_reset(struct ata_port *ap, unsigned int *classes) { + struct pci_dev *pdev = to_pci_dev(ap->host_set->dev); + + /* Workaround for VIA VT8251 "busy" bug */ + if (pdev->device == 0x3349) { + if (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); - : send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
