[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 at 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