Re: [EXTERNAL] Re: [PATCH] arm64: defconfig: enable PCIe controller on TI platforms

From: Verma, Achal
Date: Tue May 09 2023 - 05:20:46 EST



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@xxxxxxxxxxxxxx/
[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