diff options
| author | Shashank Babu Chinta Venkata <quic_schintav@quicinc.com> | 2024-09-11 20:56:28 +0530 |
|---|---|---|
| committer | Krzysztof Wilczyński <kwilczynski@kernel.org> | 2024-09-13 14:44:57 +0000 |
| commit | d45736b5984954da71292d858f277bac9c70cd2e (patch) | |
| tree | 0fc202a917dc949a0b645ee662f57a2423d2add7 /drivers/pci/controller/dwc/pcie-tegra194.c | |
| parent | 19a69cbd9d436fe503e5cb6dade76fe371244d4f (diff) | |
PCI: qcom: Add equalization settings for 16.0 GT/s
During high data transmission rates such as 16.0 GT/s, there is an
increased risk of signal loss due to poor channel quality and
interference. This can impact receiver's ability to capture signals
accurately.
Hence, as signal compensation is achieved through appropriate lane
equalization, apply lane equalization settings at both transmitter
and receiver which results in an increase in the PCIe signal strength.
While at it, modify the pcie-tegra194 driver to make use of the
common GEN3_EQ_CONTROL_OFF definitions in pcie-designware.h.
Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-3-743f5c1fd027@linaro.org
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
[mani: dropped the code refactoring and minor changes]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-tegra194.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-tegra194.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index 4bf7b433417a..6e03e14151d6 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -177,11 +177,6 @@ #define N_FTS_VAL 52 #define FTS_VAL 52 -#define GEN3_EQ_CONTROL_OFF 0x8a8 -#define GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_SHIFT 8 -#define GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK GENMASK(23, 8) -#define GEN3_EQ_CONTROL_OFF_FB_MODE_MASK GENMASK(3, 0) - #define PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT 0x8D0 #define AMBA_ERROR_RESPONSE_CRS_SHIFT 3 #define AMBA_ERROR_RESPONSE_CRS_MASK GENMASK(1, 0) @@ -861,9 +856,9 @@ static void config_gen3_gen4_eq_presets(struct tegra_pcie_dw *pcie) dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val); val = dw_pcie_readl_dbi(pci, GEN3_EQ_CONTROL_OFF); - val &= ~GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK; - val |= (0x3ff << GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_SHIFT); - val &= ~GEN3_EQ_CONTROL_OFF_FB_MODE_MASK; + val &= ~GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC; + val |= FIELD_PREP(GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC, 0x3ff); + val &= ~GEN3_EQ_CONTROL_OFF_FB_MODE; dw_pcie_writel_dbi(pci, GEN3_EQ_CONTROL_OFF, val); val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF); @@ -872,10 +867,10 @@ static void config_gen3_gen4_eq_presets(struct tegra_pcie_dw *pcie) dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val); val = dw_pcie_readl_dbi(pci, GEN3_EQ_CONTROL_OFF); - val &= ~GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK; - val |= (pcie->of_data->gen4_preset_vec << - GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_SHIFT); - val &= ~GEN3_EQ_CONTROL_OFF_FB_MODE_MASK; + val &= ~GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC; + val |= FIELD_PREP(GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC, + pcie->of_data->gen4_preset_vec); + val &= ~GEN3_EQ_CONTROL_OFF_FB_MODE; dw_pcie_writel_dbi(pci, GEN3_EQ_CONTROL_OFF, val); val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF); |