Florian Effenberger wrote:
> Hi,
>
>> Currently, there is no mechanism to do that but hard drives usually have
>> dip switch to force 1.5Gbps. Please try that. If your harddrive
>> doesn't have that, please lemme know. I'll prepare a simple patch.
>
> unfortunately, the disks have a jumper board, but the jumpers are
> missing... could you write a patch for me? Would be much appreciated!
Okay, there was a bug in link speed limit logic. That's probably why
speed down to 1.5Gbps didn't kick in. The attached patch contains the
fix and hack to force 1.5Gbps. Please give it a shot.
Thanks.
--
tejun
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 7baeaff..f9550f1 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -219,6 +219,7 @@ static int ahci_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc);
static void ahci_irq_clear(struct ata_port *ap);
static int ahci_port_start(struct ata_port *ap);
+static int ahci_vt8251_port_start(struct ata_port *ap);
static void ahci_port_stop(struct ata_port *ap);
static void ahci_tf_read(struct ata_port *ap, struct ata_taskfile *tf);
static void ahci_qc_prep(struct ata_queued_cmd *qc);
@@ -284,7 +285,7 @@ static const struct ata_port_operations ahci_ops = {
.port_resume = ahci_port_resume,
#endif
- .port_start = ahci_port_start,
+ .port_start = ahci_vt8251_port_start,
.port_stop = ahci_port_stop,
};
@@ -318,7 +319,7 @@ static const struct ata_port_operations ahci_vt8251_ops = {
.port_resume = ahci_port_resume,
#endif
- .port_start = ahci_port_start,
+ .port_start = ahci_vt8251_port_start,
.port_stop = ahci_port_stop,
};
@@ -1558,6 +1559,19 @@ static int ahci_port_start(struct ata_port *ap)
return 0;
}
+static int ahci_vt8251_port_start(struct ata_port *ap)
+{
+ struct ahci_host_priv *hpriv = ap->host->private_data;
+
+ if (((hpriv->cap >> 20) & 0xf) != 1) {
+ printk("limiting SATA link speed to 1.5Gbps\n");
+ ap->hw_sata_spd_limit = 1;
+ ap->eh_info.action |= ATA_EH_HARDRESET;
+ }
+
+ return ahci_port_start(ap);
+}
+
static void ahci_port_stop(struct ata_port *ap)
{
const char *emsg = NULL;
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 4733f00..57940ba 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6313,7 +6313,8 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
/* init sata_spd_limit to the current value */
if (sata_scr_read(ap, SCR_CONTROL, &scontrol) == 0) {
int spd = (scontrol >> 4) & 0xf;
- ap->hw_sata_spd_limit &= (1 << spd) - 1;
+ if (spd)
+ ap->hw_sata_spd_limit &= (1 << spd) - 1;
}
ap->sata_spd_limit = ap->hw_sata_spd_limit;
