Re: [PATCH v3] PCI: keystone: Fix pci_ops for AM654x SoC

From: Siddharth Vadapalli
Date: Wed Oct 25 2023 - 06:58:58 EST


Serge,

On 25/10/23 15:58, Serge Semin wrote:
> Hi Siddharth, Bjorn
>
> On Wed, Oct 25, 2023 at 10:32:50AM +0530, Siddharth Vadapalli wrote:

...

>>
>
>> ks_pcie_probe()
>> dw_pcie_host_init()
>> pci_host_probe()
>> ks_pcie_v3_65_add_bus()
>
> I guess what Bjorn implied was to add the ks_pcie_v3_65_add_bus()
> invocation to the host_init() callback, i.e. in ks_pcie_host_init().

I misunderstood the term "host_init()", and interpret it as
"dw_pcie_host_init()", due to which I thought I will add it after
dw_pcie_host_init() invocation in ks_pcie_probe. Thank you for clarifying.

> Moreover initializing the BARs/MSI after all the PCIe hierarchy has
> been probed will eventually cause problems since MSI's won't work
> until the ks_pcie_v3_65_add_bus() is called.
>
>>
>> Since the .add_bus() method will be removed following this change, I suppose
>> that the patch I post for it can be applied instead of this v3 patch which fixes
>> pci_ops.
>>
>
>> The patch I plan to post as a replacement for the current patch which shall also
>> remove the ks_pcie_v3_65_add_bus() and the .add_bus() method is:
>
> Just a note. Seeing the Bjorn's suggestion may cause a regression on
> the Keystone PCIe Host v3.65 I would suggest to merge in the original
> fix as is and post an additional cleanup patch, like below with proper
> modifications, on top of it. Thus we'll minimize a risk to break
> things at least on the stable kernels.

I will post it as a separate cleanup patch in that case and this v3 patch can be
merged independently as you suggested.

--
Regards,
Siddharth.