[RFC 8/9] PCI/pwrseq: add a pwrseq driver for QCA6390

[Kalle Valo]

"Arnd Bergmann" <arnd at arndb.de> writes:

> On Tue, Jan 9, 2024, at 11:09, Kalle Valo wrote:
>
>> Chen-Yu Tsai <wenst at chromium.org> writes:
>>> On Tue, Jan 9, 2024 at 5:18 PM Kalle Valo <kvalo at kernel.org> wrote:
>>>> Jeff Johnson <quic_jjohnson at quicinc.com> writes:
>>>>
>>>> > On 1/4/2024 5:01 AM, Bartosz Golaszewski wrote:
>>>> >> diff --git a/drivers/pci/pcie/pwrseq/Kconfig b/drivers/pci/pcie/pwrseq/Kconfig
>>>> >> index 010e31f432c9..f9fe555b8506 100644
>>>> >> --- a/drivers/pci/pcie/pwrseq/Kconfig
>>>> >> +++ b/drivers/pci/pcie/pwrseq/Kconfig
>>>> >> @@ -6,3 +6,14 @@ menuconfig PCIE_PWRSEQ
>>>> >>      help
>>>> >>        Say yes here to enable support for PCIe power sequencing
>>>> >>        drivers.
>>>> >> +
>>>> >> +if PCIE_PWRSEQ
>>>> >> +
>>>> >> +config PCIE_PWRSEQ_QCA6390
>>>> >> +    tristate "PCIe Power Sequencing driver for QCA6390"
>>>> >> +    depends on ARCH_QCOM || COMPILE_TEST
>>>> >> +    help
>>>> >> +      Enable support for the PCIe power sequencing driver for the
>>>> >> +      ath11k module of the QCA6390 WLAN/BT chip.
>>>> >> +
>>>> >> +endif
>>>> >
>>>> > As I mentioned in the 5/9 patch I'm concerned that the current
>>>> > definition of PCIE_PWRSEQ and PCIE_PWRSEQ_QCA6390 will effectively hide
>>>> > the fact that QCA6390 may need additional configuration since the menu
>>>> > item will only show up if you have already enabled PCIE_PWRSEQ.
>>>> > Yes I see that these are set in the defconfig in 9/9 but I'm concerned
>>>> > about the more generic case.
>>>> >
>>>> > I'm wondering if there should be a separate config QCA6390 within ath11k
>>>> > which would then select PCIE_PWRSEQ and PCIE_PWRSEQ_QCA6390
>>>>
>>>> Or is it possible to provide an optional dependency in Kconfig (I guess
>>>
>>> imply PCIE_PWRSEQ
>>> imply PCIE_PWRSEQ_QCA6390
>>> ?
>>
>> Nice, I had forgotten imply altogether. Would 'imply
>> PCIE_PWRSEQ_QCA6390' in ath11k Kconfig be enough to address Jeff's
>> concern?
>
> Please don't use imply (ever), it doesn't normally do
> what you want. In this case, the only effect the
> 'imply' has is to change the default of the PCIE_PWRSEQ_QCA6390
> option when a defconfig contains QCA6390.
>
> If this is indeed what you want, it's still better to do the
> equivalent expression in PCIE_PWRSEQ_QCA6390 rather than ATH11K:
>
> config PCIE_PWRSEQ_QCA6390
>       tristate "PCIe Power Sequencing driver for QCA6390"
>       default ATH11K && ARCH_QCOM

Sounds good to me but should it be 'default ATH11K_PCI && ARCH_QCOM'? My
understanding is that we don't need PWRSEQ for ATH11K_AHB devices.

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