From: Marcin Tomczak <marcin.tomczak@xxxxxxxxx>
Need the following workaround in the driver for interoperability with
the older Intel SSD drives and any other SATA drive that may exhibit the
same behavior. This is a corner case where SCU speed is limited to
either 3G or 1.5G and the drive has a period of DC idle when it switches
speed during SATA speed negotiation. Workaround :change PHYTOV[31:24]
from 0x36 to 0x3B.
Signed-off-by: Marcin Tomczak <marcin.tomczak@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/scsi/isci/phy.c | 13 +++++++++++++
drivers/scsi/isci/registers.h | 12 ++++++++++++
2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/isci/phy.c b/drivers/scsi/isci/phy.c
index 79313a7..430fc8f 100644
--- a/drivers/scsi/isci/phy.c
+++ b/drivers/scsi/isci/phy.c
@@ -104,6 +104,7 @@ sci_phy_link_layer_initialization(struct isci_phy *iphy,
u32 parity_count = 0;
u32 llctl, link_rate;
u32 clksm_value = 0;
+ u32 sp_timeouts = 0;
iphy->link_layer_registers = reg;
@@ -211,6 +212,18 @@ sci_phy_link_layer_initialization(struct isci_phy *iphy,
llctl |= SCU_SAS_LLCTL_GEN_VAL(MAX_LINK_RATE, link_rate);
writel(llctl, &iphy->link_layer_registers->link_layer_control);
+ sp_timeouts = readl(&iphy->link_layer_registers->sas_phy_timeouts);
+
+ /* Clear the default 0x36 (54us) RATE_CHANGE timeout value. */
+ sp_timeouts &= ~SCU_SAS_PHYTOV_GEN_VAL(RATE_CHANGE, 0xFF);
+
+ /* Set RATE_CHANGE timeout value to 0x3B (59us). This ensures SCU can
+ * lock with 3Gb drive when SCU max rate is set to 1.5Gb.
+ */
+ sp_timeouts |= SCU_SAS_PHYTOV_GEN_VAL(RATE_CHANGE, 0x3B);
+
+ writel(sp_timeouts, &iphy->link_layer_registers->sas_phy_timeouts);
+
if (is_a2(ihost->pdev)) {
/* Program the max ARB time for the PHY to 700us so we inter-operate with
* the PMC expander which shuts down PHYs if the expander PHY generates too
diff --git a/drivers/scsi/isci/registers.h b/drivers/scsi/isci/registers.h
index 9b266c7..00afc73 100644
--- a/drivers/scsi/isci/registers.h
+++ b/drivers/scsi/isci/registers.h
@@ -1299,6 +1299,18 @@ struct scu_transport_layer_registers {
#define SCU_AFE_XCVRCR_OFFSET 0x00DC
#define SCU_AFE_LUTCR_OFFSET 0x00E0
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_ALIGN_DETECTION_SHIFT (0UL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_ALIGN_DETECTION_MASK (0x000000FFUL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_HOT_PLUG_SHIFT (8UL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_HOT_PLUG_MASK (0x0000FF00UL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_COMSAS_DETECTION_SHIFT (16UL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_COMSAS_DETECTION_MASK (0x00FF0000UL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_RATE_CHANGE_SHIFT (24UL)
+#define SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_RATE_CHANGE_MASK (0xFF000000UL)
+
+#define SCU_SAS_PHYTOV_GEN_VAL(name, value) \
+ SCU_GEN_VALUE(SCU_SAS_PHY_TIMER_TIMEOUT_VALUES_##name, value)
+
#define SCU_SAS_LINK_LAYER_CONTROL_MAX_LINK_RATE_SHIFT (0)
#define SCU_SAS_LINK_LAYER_CONTROL_MAX_LINK_RATE_MASK (0x00000003)
#define SCU_SAS_LINK_LAYER_CONTROL_MAX_LINK_RATE_GEN1 (0)
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
