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| author | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2024-09-11 18:26:27 +0300 |
|---|---|---|
| committer | Krzysztof Wilczyński <kwilczynski@kernel.org> | 2024-09-13 17:44:55 +0300 |
| commit | 19a69cbd9d436fe503e5cb6dade76fe371244d4f (patch) | |
| tree | b4cedb111843962aa9de497c815c18db7d6fc2e3 /drivers/pci/controller | |
| parent | 2cebf68a24abb0552ea59cf928829acd51f8b175 (diff) | |
| download | linux-19a69cbd9d436fe503e5cb6dade76fe371244d4f.tar.xz | |
PCI: dwc: Always cache the maximum link speed value in dw_pcie::max_link_speed
Currently, the dw_pcie::max_link_speed has a valid value only if the
controller driver restricts the maximum link speed in the driver or if
the platform does so in the devicetree using the 'max-link-speed'
property.
But having the maximum supported link speed of the platform would be
helpful for the vendor drivers to configure any link specific settings.
So in the case of non-valid value in dw_pcie::max_link_speed, just cache
the hardware default value from Link Capability register.
While at it, remove the 'max_link_speed' argument to the
dw_pcie_link_set_max_speed() function since the value can be
retrieved within the function.
Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-2-743f5c1fd027@linaro.org
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Diffstat (limited to 'drivers/pci/controller')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 95ae6c65b28f..6d6cbc8b5b2c 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -689,16 +689,27 @@ void dw_pcie_upconfig_setup(struct dw_pcie *pci) } EXPORT_SYMBOL_GPL(dw_pcie_upconfig_setup); -static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 max_link_speed) +static void dw_pcie_link_set_max_speed(struct dw_pcie *pci) { u32 cap, ctrl2, link_speed; u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); cap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); + + /* + * Even if the platform doesn't want to limit the maximum link speed, + * just cache the hardware default value so that the vendor drivers can + * use it to do any link specific configuration. + */ + if (pci->max_link_speed < 1) { + pci->max_link_speed = FIELD_GET(PCI_EXP_LNKCAP_SLS, cap); + return; + } + ctrl2 = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCTL2); ctrl2 &= ~PCI_EXP_LNKCTL2_TLS; - switch (pcie_link_speed[max_link_speed]) { + switch (pcie_link_speed[pci->max_link_speed]) { case PCIE_SPEED_2_5GT: link_speed = PCI_EXP_LNKCTL2_TLS_2_5GT; break; @@ -1060,8 +1071,7 @@ void dw_pcie_setup(struct dw_pcie *pci) { u32 val; - if (pci->max_link_speed > 0) - dw_pcie_link_set_max_speed(pci, pci->max_link_speed); + dw_pcie_link_set_max_speed(pci); /* Configure Gen1 N_FTS */ if (pci->n_fts[0]) { |