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Date:   Tue, 9 May 2023 14:49:32 +0530
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Subject: Re: [EXTERNAL] Re: [PATCH] arm64: defconfig: enable PCIe controller
 on TI platforms
To:     Arnd Bergmann <arnd@arndb.de>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Bjorn Andersson <quic_bjorande@quicinc.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= 
        <nfraprado@collabora.com>, Mark Brown <broonie@kernel.org>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>,
        Nishanth Menon <nm@ti.com>, Milind Parab <mparab@cadence.com>,
        Swapnil Kashinath Jakhade <sjakhade@cadence.com>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, Achal Verma <a-verma1@ti.com>
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 <de6432db-0da0-b535-1f44-04541116be8b@ti.com>
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From:   "Verma, Achal" <a-verma1@ti.com>
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Hello,
On 5/9/2023 1:58 PM, Arnd Bergmann wrote:
> On Tue, May 9, 2023, at 10:08, Vignesh Raghavendra wrote:
> 
>> Also, see [0] for history. We really want these to be
>> modules unless its necessary for bootup.
>>
>> You may want to revive [1] and get it to mainline
>>
>> [0]
>> https://lore.kernel.org/linux-arm-kernel/CAK8P3a2VSBvOn1o+q1PYZaQ6LS9U4cz+DZGuDbisHkwNs2dAAw@mail.gmail.com/
>> [1]
>> https://lore.kernel.org/linux-arm-kernel/20230110153805.GA1505901@bhelgaas/
> 
> Agreed, that seems simple enough. Ideally these should even
> be removable modules, not just single-load but unremovable.
> 
> Doing that may require changes to the cadence PCIe host
> code if that does not support unloading yet (I have not
> checked), but should not require any changes to the core
> PCIe host code that supports loadable/removable modules.
> 
>       Arnd
So, my understanding is that following change is expected
+CONFIG_PCIE_CADENCE=m
+CONFIG_PCIE_CADENCE_HOST=m
+CONFIG_PCIE_CADENCE_EP=m
+CONFIG_PCI_J721E=m
+CONFIG_PCI_J721E_HOST=m
+CONFIG_PCI_J721E_EP=m
+CONFIG_PCI_EPF_NTB=m

I also want to inform that pci_j721e.c is a single file with both host 
and EP functionality, last attempt to build it as modules depending on 
host or EP selected failed because of symbols dependency.
Refactoring of pci_j721e.c into common, host and EP specific files could 
work similar to the Cadence driver, So I will follow this way and push 
the changes.

Please let me know if there are concerns.


Thanks,
Achal Verma