On 08/06/2021 19:34, Vidya Sagar wrote:
...
>>> What is the purpose of PCIE_TEGRA194_EP (added by c57247f940e8 ("PCI:
>>> tegra: Add support for PCIe endpoint mode in Tegra194") [1])? I don't
>>> see any reference to it in a makefile or a source file.
>>>
>>> It looks like one can build a single driver that works in either host
>>> or endpoint mode, depending on whether a DT node matches
>>> "nvidia,tegra194-pcie" or "nvidia,tegra194-pcie-ep".
>>>
>>> So I think PCIE_TEGRA194_EP is superfluous and should be removed and
>>> you should have a single tristate Kconfig option.
>>
>> This is a good point.
>>
>> Sagar, any reason for this?
> Although it is the same driver that works for both HOST mode and EP
> mode, PCIE_TEGRA194_EP depends on PCI_ENDPOINT whereas the
> PCIE_TEGRA194_HOST mode doesn't. Similarly the PCIE_TEGRA194_HOST mode
> depends on PCI_MSI_IRQ_DOMAIN which PCIE_TEGRA194_EP doesn't depend on.
> It is possible to have end point mode support disabled (at sub-system
> level) in the system yet pcie-tegra194 can be compiled for the host mode
> vice-a-versa for the endpoint mode.
> Hence, appropriate config HOST/EP needs to be selected to make sure that
> the rest of the dependencies are enabled in the system.
> Hope I'm able to give the rationale correctly here.
Yes but should we combine them like this ...
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 423d35872ce4..206455a9b70d 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -254,15 +254,12 @@ config PCI_MESON
implement the driver.
config PCIE_TEGRA194
- tristate
-
-config PCIE_TEGRA194_HOST
- tristate "NVIDIA Tegra194 (and later) PCIe controller - Host Mode"
+ tristate "NVIDIA Tegra194 (and later) PCIe controller"
depends on ARCH_TEGRA_194_SOC || COMPILE_TEST
- depends on PCI_MSI_IRQ_DOMAIN
- select PCIE_DW_HOST
+ depends on PCI_MSI_IRQ_DOMAIN || PCI_ENDPOINT
+ select PCIE_DW_HOST if PCI_MSI_IRQ_DOMAIN
+ select PCIE_DW_EP if PCI_ENDPOINT
select PHY_TEGRA194_P2U
- select PCIE_TEGRA194
help
Enables support for the PCIe controller in the NVIDIA Tegra194 SoC to
work in host mode. There are two instances of PCIe controllers in
@@ -271,21 +268,6 @@ config PCIE_TEGRA194_HOST
in order to enable device-specific features PCIE_TEGRA194_EP must be
selected. This uses the DesignWare core.
-config PCIE_TEGRA194_EP
- tristate "NVIDIA Tegra194 (and later) PCIe controller - Endpoint Mode"
- depends on ARCH_TEGRA_194_SOC || COMPILE_TEST
- depends on PCI_ENDPOINT
- select PCIE_DW_EP
- select PHY_TEGRA194_P2U
- select PCIE_TEGRA194
- help
- Enables support for the PCIe controller in the NVIDIA Tegra194 SoC to
- work in endpoint mode. There are two instances of PCIe controllers in
- Tegra194. This controller can work either as EP or RC. In order to
- enable host-specific features PCIE_TEGRA194_HOST must be selected and
- in order to enable device-specific features PCIE_TEGRA194_EP must be
- selected. This uses the DesignWare core.
-
Furthermore, I wonder if we should just move the code
that is required for ACPI into it's own file like
drivers/pci/controller/dwc/pcie-tegra194-acpi.c?
Jon
--
nvpublic
