Re: [PATCH v7 2/3] dwc: PCI: intel: PCIe RC controller driver

[Jingoo Han <jingoohan1@gmail.com>]

On 11/18/19, 8:26 PM, Dilip Kota wrote:
> 
> On 11/19/2019 12:40 AM, Jingoo Han wrote:
> >
> > On 11/18/19, 2:58 AM, Dilip Kota wrote:
> >
> >> On 11/16/2019 4:40 AM, Jingoo Han wrote:
> >>> On 11/14/19, 9:31 PM, Dilip Kota wrote:
> >>>
> >>>> Add support to PCIe RC controller on Intel Gateway SoCs.
> >>>> PCIe controller is based of Synopsys DesignWare PCIe core.
> >>>>
> >>>> Intel PCIe driver requires Upconfigure support, Fast Training
> >>>> Sequence and link speed configurations. So adding the respective
> >>>> helper functions in the PCIe DesignWare framework.
> >>>> It also programs hardware autonomous speed during speed
> >>>> configuration so defining it in pci_regs.h.
> >>>>
> >>>> Signed-off-by: Dilip Kota <eswara.kota@linux.intel.com>
> >>>> Reviewed-by: Andrew Murray <andrew.murray@arm.com>
> >>>> Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> >>>> ---
> >>> [.....]
> >>>
> >>>>    drivers/pci/controller/dwc/Kconfig           |  10 +
> >>>>    drivers/pci/controller/dwc/Makefile          |   1 +
> >>>>    drivers/pci/controller/dwc/pcie-designware.c |  57 +++
> >>>>    drivers/pci/controller/dwc/pcie-designware.h |  12 +
> >>>>    drivers/pci/controller/dwc/pcie-intel-gw.c   | 542 +++++++++++++++++++++++++++
> >>>>    include/uapi/linux/pci_regs.h                |   1 +
> >>>>    6 files changed, 623 insertions(+)
> >>>>    create mode 100644 drivers/pci/controller/dwc/pcie-intel-gw.c
> >>>>
> >>>> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> >>>> index 0ba988b5b5bc..fb6d474477df 100644
> >>>> --- a/drivers/pci/controller/dwc/Kconfig
> >>>> +++ b/drivers/pci/controller/dwc/Kconfig
> >>>> @@ -82,6 +82,16 @@ config PCIE_DW_PLAT_EP
> >>>>    	  order to enable device-specific features PCI_DW_PLAT_EP must be
> >>>>    	  selected.
> >>>>    
> >>>> +config PCIE_INTEL_GW
> >>>> +	bool "Intel Gateway PCIe host controller support"
> >>>> +	depends on OF && (X86 || COMPILE_TEST)
> >>>> +	select PCIE_DW_HOST
> >>>> +	help
> >>>> +	  Say 'Y' here to enable PCIe Host controller support on Intel
> >>>> +	  Gateway SoCs.
> >>>> +	  The PCIe controller uses the DesignWare core plus Intel-specific
> >>>> +	  hardware wrappers.
> >>>> +
> >>> Please add this config alphabetical order!
> >>> So, this config should be after 'config PCI_IMX6'.
> >>> There is no reason to put this config at the first place.
> >>>
> >>>>    config PCI_EXYNOS
> >>>>    	bool "Samsung Exynos PCIe controller"
> >>>>    	depends on SOC_EXYNOS5440 || COMPILE_TEST
> >>>> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> >>>> index b30336181d46..99db83cd2f35 100644
> >>>> --- a/drivers/pci/controller/dwc/Makefile
> >>>> +++ b/drivers/pci/controller/dwc/Makefile
> >>>> @@ -3,6 +3,7 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
> >>>>    obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o
> >>>>    obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
> >>>>    obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
> >>>> +obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o
> >>> Ditto.
> >> PCIE_INTEL_GW wouldnt come after PCI_IMX6, the complete Makefile and
> >> Kconfig are not in order,( PCI_* and PCIE_* are not in any order). So i
> >> just followed PCIE_DW and placed PCIE_INTEL_GW after PCIE_DW as I is
> >> after D (and i see PCI_* immediately after the PCIE_DW*, so i placed
> >> PCIE_INTEL_GW after PCIE_DW* and before PCI_*).
> > Hey, although some of them are not in order, you don't have a right to do so.
> > If some people do not follow the law, it does not mean that you can break the law.
> > Anyway, if you don't follow an alphabetical order, my answer is NACK.
> > Also, other people or I will send a patch to fix the order of other drivers.
>
> I am not against following the order. I kept PCIE_INTEL_GW after 
> PCIE_DW* by checking the best possible order.
> As per the alphabetical order, i see all CONFIG_PCIE_* comes first and 
> CONFIG_PCI_* follows. So, by following this, i placed PCIE_INTEL_GW 
> after PCIE_DW* (for the same reason PCIE_INTEL_GW cannot be placed after 
> PCI_IMX6).
> Even after re-ordering the Kconfig and Makefile, still PCIE_INTEL_GW 
> comes after PCIE_DW_PLAT( and PCIE_HISI_STB).

Are you kidding me?

Most PCIE_* drivers are located after PCI_*. Look at PCIE_QCOM, PCIE_ARMADA_8K,
PCIE_ARTPEC6, PCIE_KIRIN, PCIE_HISI_STB, PCIE_TEGRA194, PCIE_UNIPHIER, PCIE_AL.
Put PCIE_INTEL_GW between PCIE_ARTPEC6_EP and PCIE_KIRIN.


> Regards,
Dilip

>
>
>> Regards,
>> Dilip
>> Best regards,
>> Jingoo Han
>>
>>>    obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
>>>    obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
>>>    obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
>>> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
>>> index 820488dfeaed..479e250695a0 100644
>> [.....]