On Tue, 11 Apr 2006 19:15:45 +0200 Bastiaan Jacques wrote: > 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 */ You can add a separate host type (e.g., board_via_vt8251_ahci), and then add an entry for this type to ahci_port_info[]. The entry would have a special flag in .host_flags, but the same .port_ops, so there will not be excessive duplication like in the original vendor patch. Look like other drivers which need workarounds for hardware bugs (e.g., sata_sil) do this. > { } /* 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; > The following empty line should probably be deleted too. > 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) { After adding a separate host type and a host flag this will be: if (ap->flags & AHCI_FLAG_RESET_NEEDS_CLO) { > + 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);
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