[PATCH v2 1/2] phy: qcom-qmp-pcie: Fix high latency with 4x2 PHY when ASPM is enabled

[PATCH v2 1/2] phy: qcom-qmp-pcie: Fix high latency with 4x2 PHY when ASPM is enabled

[Manivannan Sadhasivam]

The PCIe QMP 4x2 RC PHY generates high latency when ASPM is enabled. This
seem to be fixed by clearing the QPHY_V5_20_PCS_PCIE_PRESET_P10_POST
register of the pcs_misc register space.

Fixes: 2c91bf6bf290 ("phy: qcom-qmp: Add SM8450 PCIe1 PHY support")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---

Changes in v2

* Dropped the changes to PCS_PCIE_EQ_CONFIG{2/3} registers and added
a new PCS_PCIE_PRESET_P10_POST register

 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c           | 1 +
 drivers/phy/qualcomm/phy-qcom-qmp-pcs-pcie-v5_20.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index f3f75eda01a6..9473f63d2c1c 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -1305,6 +1305,7 @@ static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_pcs_misc_tbl[] = {
 static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_rc_pcs_misc_tbl[] = {
 	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_PCIE_ENDPOINT_REFCLK_DRIVE, 0xc1),
 	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_PCIE_OSC_DTCT_ACTIONS, 0x00),
+	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_PCIE_PRESET_P10_POST, 0x00),
 };
 
 static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_ep_serdes_tbl[] = {
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcs-pcie-v5_20.h b/drivers/phy/qualcomm/phy-qcom-qmp-pcs-pcie-v5_20.h
index c9fa90b45475..3d9713d348fe 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcs-pcie-v5_20.h
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcs-pcie-v5_20.h
@@ -11,6 +11,7 @@
 #define QPHY_V5_20_PCS_PCIE_OSC_DTCT_MODE2_CONFIG5	0x084
 #define QPHY_V5_20_PCS_PCIE_OSC_DTCT_ACTIONS		0x090
 #define QPHY_V5_20_PCS_PCIE_EQ_CONFIG1			0x0a0
+#define QPHY_V5_20_PCS_PCIE_PRESET_P10_POST		0x0e0
 #define QPHY_V5_20_PCS_PCIE_G4_EQ_CONFIG5		0x108
 #define QPHY_V5_20_PCS_PCIE_G4_PRE_GAIN			0x15c
 #define QPHY_V5_20_PCS_PCIE_RX_MARGINING_CONFIG3	0x184
-- 
2.25.1

[PATCH v2 2/2] phy: qcom-qmp-pcie: Fix sm8450_qmp_gen4x2_pcie_pcs_tbl[] register names

[Manivannan Sadhasivam]

sm8450_qmp_gen4x2_pcie_pcs_tbl[] contains the init sequence for PCS
registers of QMP PHY v5.20. So use the v5.20 specific register names.
Only major change is the rename of PCS_EQ_CONFIG{2/3} registers to
PCS_EQ_CONFIG{4/5}.

Fixes: 2c91bf6bf290 ("phy: qcom-qmp: Add SM8450 PCIe1 PHY support")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---

Changes in v2:

* New patch

 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c      |  8 ++++----
 drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5_20.h | 14 ++++++++++++++
 drivers/phy/qualcomm/phy-qcom-qmp.h           |  1 +
 3 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5_20.h

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 9473f63d2c1c..71bb86c3deff 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -1289,10 +1289,10 @@ static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_rx_tbl[] = {
 };
 
 static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_pcs_tbl[] = {
-	QMP_PHY_INIT_CFG(QPHY_V5_PCS_EQ_CONFIG2, 0x16),
-	QMP_PHY_INIT_CFG(QPHY_V5_PCS_EQ_CONFIG3, 0x22),
-	QMP_PHY_INIT_CFG(QPHY_V5_PCS_G3S2_PRE_GAIN, 0x2e),
-	QMP_PHY_INIT_CFG(QPHY_V5_PCS_RX_SIGDET_LVL, 0x99),
+	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_EQ_CONFIG4, 0x16),
+	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_EQ_CONFIG5, 0x22),
+	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_G3S2_PRE_GAIN, 0x2e),
+	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_RX_SIGDET_LVL, 0x99),
 };
 
 static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_pcs_misc_tbl[] = {
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5_20.h b/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5_20.h
new file mode 100644
index 000000000000..9a5a20daf62c
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5_20.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022, Linaro Ltd.
+ */
+
+#ifndef QCOM_PHY_QMP_PCS_V5_20_H_
+#define QCOM_PHY_QMP_PCS_V5_20_H_
+
+#define QPHY_V5_20_PCS_G3S2_PRE_GAIN			0x170
+#define QPHY_V5_20_PCS_RX_SIGDET_LVL			0x188
+#define QPHY_V5_20_PCS_EQ_CONFIG4			0x1e0
+#define QPHY_V5_20_PCS_EQ_CONFIG5			0x1e4
+
+#endif
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.h b/drivers/phy/qualcomm/phy-qcom-qmp.h
index 26274e3c0cf9..29a48f0436d2 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.h
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.h
@@ -38,6 +38,7 @@
 #include "phy-qcom-qmp-pcs-pcie-v4_20.h"
 
 #include "phy-qcom-qmp-pcs-v5.h"
+#include "phy-qcom-qmp-pcs-v5_20.h"
 #include "phy-qcom-qmp-pcs-pcie-v5.h"
 #include "phy-qcom-qmp-pcs-usb-v5.h"
 #include "phy-qcom-qmp-pcs-ufs-v5.h"
-- 
2.25.1

Re: [PATCH v2 1/2] phy: qcom-qmp-pcie: Fix high latency with 4x2 PHY when ASPM is enabled

[Vinod Koul]

On 02-11-22, 13:48, Manivannan Sadhasivam wrote:
> The PCIe QMP 4x2 RC PHY generates high latency when ASPM is enabled. This
> seem to be fixed by clearing the QPHY_V5_20_PCS_PCIE_PRESET_P10_POST
> register of the pcs_misc register space.

Applied, thanks

-- 
~Vinod