Re: [PATCH] phy: qcom-qmp-pcie: Fix the SM8450 PCS registers

From: Dmitry Baryshkov
Date: Wed Sep 21 2022 - 09:06:19 EST


On 10/09/2022 09:38, Manivannan Sadhasivam wrote:
In the PCS region, registers QPHY_V5_PCS_EQ_CONFIG4 and
QPHY_V5_PCS_EQ_CONFIG5 should be used instead of QPHY_V5_PCS_EQ_CONFIG2
and QPHY_V5_PCS_EQ_CONFIG3.

This causes high latency when ASPM is enabled, so fix it!

I have checked against vendor's tree [1]. The registers in question have offsets 0x01c0f3e0 / 0x01c0f3e4. The sm8450.dtsi uses 0x1c0f200 as the PCS region base for the PCIe PHY1. Thus the correct offsets for the table are 0x1e0/0x1e4.

There might be a mistake in the name of the register, but the address corresponds to the address in the vendor's tree.

[1] https://github.com/MiCode/kernel_devicetree/blob/zeus-s-oss/qcom/waipio-pcie.dtsi#L520


Fixes: 2c91bf6bf290 ("phy: qcom-qmp: Add SM8450 PCIe1 PHY support")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 4 ++--
drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5.h | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 4648467d5cac..b508903d77d0 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -1332,8 +1332,8 @@ 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_EQ_CONFIG4, 0x16),
+ QMP_PHY_INIT_CFG(QPHY_V5_PCS_EQ_CONFIG5, 0x22),
QMP_PHY_INIT_CFG(QPHY_V5_PCS_G3S2_PRE_GAIN, 0x2e),
QMP_PHY_INIT_CFG(QPHY_V5_PCS_RX_SIGDET_LVL, 0x99),
};
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5.h b/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5.h
index 61a44519f969..cca6455ec98c 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5.h
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcs-v5.h
@@ -11,7 +11,7 @@
#define QPHY_V5_PCS_G3S2_PRE_GAIN 0x170
#define QPHY_V5_PCS_RX_SIGDET_LVL 0x188
#define QPHY_V5_PCS_RATE_SLEW_CNTRL1 0x198
-#define QPHY_V5_PCS_EQ_CONFIG2 0x1e0
-#define QPHY_V5_PCS_EQ_CONFIG3 0x1e4
+#define QPHY_V5_PCS_EQ_CONFIG4 0x2e0
+#define QPHY_V5_PCS_EQ_CONFIG5 0x2e4
#endif

--
With best wishes
Dmitry