Re: [PATCH] PCI: dwc: Separate MSI out to different controller

Manivannan Sadhasivam
2025-02-11T07:57:01Z

On Tue, Feb 11, 2025 at 03:16:11PM +0800, Tsai Sung-Fu wrote:
> Hi Mani and Bjorn,
>
> Sorry for the late reply, we just found out some problems in the patch
> we are trying to upstream here, and figuring out it might not be a
> good idea to keep this process going, so I would drop this patch
> submission, and come back once we figure it out a better way.
>
> BTW, May I ask why upstream chose to flag this driver with
> MSI_FLAG_NO_AFFINITY and remove the function dw_pci_msi_set_affinity
> implementation ?
>

Because you cannot set affinity for chained MSIs as these MSIs are muxed to
another parent interrupt. Since the IRQ affinity is all about changing which CPU
gets the IRQ, affinity setting is only possible for the MSI parent.

- Mani

--
மணிவண்ணன் சதாசிவம்