[PATCH] sata_via: use old SCR access pattern on vt6420
vt6420 has super-fragile SCR registers which can hang the whole
machine if accessed with the wrong timings. This patch makes sata_via
use SCR registers only during probing and with the same timings as
before (pre new EH), which is proven to work.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/sata_via.c b/drivers/scsi/sata_via.c
index 03baec2..01d4036 100644
--- a/drivers/scsi/sata_via.c
+++ b/drivers/scsi/sata_via.c
@@ -74,6 +74,7 @@
static int svia_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
static u32 svia_scr_read (struct ata_port *ap, unsigned int sc_reg);
static void svia_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
+static void vt6420_error_handler(struct ata_port *ap);
static const struct pci_device_id svia_pci_tbl[] = {
{ 0x1106, 0x3149, PCI_ANY_ID, PCI_ANY_ID, 0, 0, vt6420 },
@@ -107,7 +108,38 @@
.bios_param = ata_std_bios_param,
};
-static const struct ata_port_operations svia_sata_ops = {
+static const struct ata_port_operations vt6420_sata_ops = {
+ .port_disable = ata_port_disable,
+
+ .tf_load = ata_tf_load,
+ .tf_read = ata_tf_read,
+ .check_status = ata_check_status,
+ .exec_command = ata_exec_command,
+ .dev_select = ata_std_dev_select,
+
+ .bmdma_setup = ata_bmdma_setup,
+ .bmdma_start = ata_bmdma_start,
+ .bmdma_stop = ata_bmdma_stop,
+ .bmdma_status = ata_bmdma_status,
+
+ .qc_prep = ata_qc_prep,
+ .qc_issue = ata_qc_issue_prot,
+ .data_xfer = ata_pio_data_xfer,
+
+ .freeze = ata_bmdma_freeze,
+ .thaw = ata_bmdma_thaw,
+ .error_handler = vt6420_error_handler,
+ .post_internal_cmd = ata_bmdma_post_internal_cmd,
+
+ .irq_handler = ata_interrupt,
+ .irq_clear = ata_bmdma_irq_clear,
+
+ .port_start = ata_port_start,
+ .port_stop = ata_port_stop,
+ .host_stop = ata_host_stop,
+};
+
+static const struct ata_port_operations vt6421_sata_ops = {
.port_disable = ata_port_disable,
.tf_load = ata_tf_load,
@@ -141,13 +173,13 @@
.host_stop = ata_host_stop,
};
-static struct ata_port_info svia_port_info = {
+static struct ata_port_info vt6420_port_info = {
.sht = &svia_sht,
.host_flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY,
.pio_mask = 0x1f,
.mwdma_mask = 0x07,
.udma_mask = 0x7f,
- .port_ops = &svia_sata_ops,
+ .port_ops = &vt6420_sata_ops,
};
MODULE_AUTHOR("Jeff Garzik");
@@ -170,6 +202,81 @@
outl(val, ap->ioaddr.scr_addr + (4 * sc_reg));
}
+/**
+ * vt6420_prereset - prereset for vt6420
+ * @ap: target ATA port
+ *
+ * SCR registers on vt6420 are pieces of shit and may hang the
+ * whole machine completely if accessed with the wrong timing.
+ * To avoid such catastrophe, vt6420 doesn't provide generic SCR
+ * access operations, but uses SStatus and SControl only during
+ * boot probing in controlled way.
+ *
+ * As the old (pre EH update) probing code is proven to work, we
+ * strictly follow the access pattern.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep)
+ *
+ * RETURNS:
+ * 0 on success, -errno otherwise.
+ */
+static int vt6420_prereset(struct ata_port *ap)
+{
+ struct ata_eh_context *ehc = &ap->eh_context;
+ unsigned long timeout = jiffies + (HZ * 5);
+ u32 sstatus, scontrol;
+ int online;
+
+ /* don't do any SCR stuff if we're not loading */
+ if (!ATA_PFLAG_LOADING)
+ goto skip_scr;
+
+ /* Resume phy. This is the old resume sequence from
+ * __sata_phy_reset().
+ */
+ svia_scr_write(ap, SCR_CONTROL, 0x300);
+ svia_scr_read(ap, SCR_CONTROL); /* flush */
+
+ /* wait for phy to become ready, if necessary */
+ do {
+ msleep(200);
+ if ((svia_scr_read(ap, SCR_STATUS) & 0xf) != 1)
+ break;
+ } while (time_before(jiffies, timeout));
+
+ /* open code sata_print_link_status() */
+ sstatus = svia_scr_read(ap, SCR_STATUS);
+ scontrol = svia_scr_read(ap, SCR_CONTROL);
+
+ online = (sstatus & 0xf) == 0x3;
+
+ ata_port_printk(ap, KERN_INFO,
+ "SATA link %s 1.5 Gbps (SStatus %X SControl %X)\n",
+ online ? "up" : "down", sstatus, scontrol);
+
+ /* SStatus is read one more time */
+ svia_scr_read(ap, SCR_STATUS);
+
+ if (!online) {
+ /* tell EH to bail */
+ ehc->i.action &= ~ATA_EH_RESET_MASK;
+ return 0;
+ }
+
+ skip_scr:
+ /* wait for !BSY */
+ ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
+
+ return 0;
+}
+
+static void vt6420_error_handler(struct ata_port *ap)
+{
+ return ata_bmdma_drive_eh(ap, vt6420_prereset, ata_std_softreset,
+ NULL, ata_std_postreset);
+}
+
static const unsigned int svia_bar_sizes[] = {
8, 4, 8, 4, 16, 256
};
@@ -210,7 +317,7 @@
static struct ata_probe_ent *vt6420_init_probe_ent(struct pci_dev *pdev)
{
struct ata_probe_ent *probe_ent;
- struct ata_port_info *ppi = &svia_port_info;
+ struct ata_port_info *ppi = &vt6420_port_info;
probe_ent = ata_pci_init_native_mode(pdev, &ppi, ATA_PORT_PRIMARY | ATA_PORT_SECONDARY);
if (!probe_ent)
@@ -239,7 +346,7 @@
probe_ent->sht = &svia_sht;
probe_ent->host_flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY;
- probe_ent->port_ops = &svia_sata_ops;
+ probe_ent->port_ops = &vt6421_sata_ops;
probe_ent->n_ports = N_PORTS;
probe_ent->irq = pdev->irq;
probe_ent->irq_flags = IRQF_SHARED;