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-rw-r--r--drivers/ata/libata-core.c29
-rw-r--r--drivers/ata/libata-eh.c6
-rw-r--r--include/linux/libata.h1
3 files changed, 29 insertions, 7 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 5718c247e23..c325b7a4246 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2389,21 +2389,35 @@ int sata_down_spd_limit(struct ata_port *ap)
u32 sstatus, spd, mask;
int rc, highbit;
+ if (!sata_scr_valid(ap))
+ return -EOPNOTSUPP;
+
+ /* If SCR can be read, use it to determine the current SPD.
+ * If not, use cached value in ap->sata_spd.
+ */
rc = sata_scr_read(ap, SCR_STATUS, &sstatus);
- if (rc)
- return rc;
+ if (rc == 0)
+ spd = (sstatus >> 4) & 0xf;
+ else
+ spd = ap->sata_spd;
mask = ap->sata_spd_limit;
if (mask <= 1)
return -EINVAL;
+
+ /* unconditionally mask off the highest bit */
highbit = fls(mask) - 1;
mask &= ~(1 << highbit);
- spd = (sstatus >> 4) & 0xf;
- if (spd <= 1)
- return -EINVAL;
- spd--;
- mask &= (1 << spd) - 1;
+ /* Mask off all speeds higher than or equal to the current
+ * one. Force 1.5Gbps if current SPD is not available.
+ */
+ if (spd > 1)
+ mask &= (1 << (spd - 1)) - 1;
+ else
+ mask &= 1;
+
+ /* were we already at the bottom? */
if (!mask)
return -EINVAL;
@@ -5995,6 +6009,7 @@ void ata_dev_init(struct ata_device *dev)
/* SATA spd limit is bound to the first device */
ap->sata_spd_limit = ap->hw_sata_spd_limit;
+ ap->sata_spd = 0;
/* High bits of dev->flags are used to record warm plug
* requests which occur asynchronously. Synchronize using
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 19f9947bd96..183eaf466d4 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1799,12 +1799,18 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
}
if (rc == 0) {
+ u32 sstatus;
+
/* After the reset, the device state is PIO 0 and the
* controller state is undefined. Record the mode.
*/
for (i = 0; i < ATA_MAX_DEVICES; i++)
ap->device[i].pio_mode = XFER_PIO_0;
+ /* record current link speed */
+ if (sata_scr_read(ap, SCR_STATUS, &sstatus) == 0)
+ ap->sata_spd = (sstatus >> 4) & 0xf;
+
if (postreset)
postreset(ap, classes);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index c732b3e78e2..16ebdf152c7 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -531,6 +531,7 @@ struct ata_port {
unsigned int cbl; /* cable type; ATA_CBL_xxx */
unsigned int hw_sata_spd_limit;
unsigned int sata_spd_limit; /* SATA PHY speed limit */
+ unsigned int sata_spd; /* current SATA PHY speed */
/* record runtime error info, protected by host lock */
struct ata_eh_info eh_info;