Re: [PATCH] PCI: dwc: Warn if the MSI ctrl doesn't have an associated platform IRQ in DT

[Manivannan Sadhasivam]

On Sat, Nov 08, 2025 at 03:48:21PM +0530, Manivannan Sadhasivam wrote:
> 
> On Thu, 30 Oct 2025 22:43:46 +0530, Manivannan Sadhasivam wrote:
> > The internal MSI controller in DWC IPs supports multiple MSI ctrls, each
> > capable of receiving 32 MSI vectors per ctrl. And each MSI ctrl requires a
> > dedicated MSI platform IRQ in devicetree to function. Otherwise, MSIs won't
> > be received from the endpoints.
> > 
> > Currently, dw_pcie_msi_host_init() only registers the IRQ handler if the
> > MSI ctrl has the associated MSI platform IRQ in DT. But it doesn't warn if
> > the IRQ is not available. This may cause developers/users to believe that
> > the platform supports MSI vectors from all MSI ctrls, but it doesn't.
> > 
> > [...]
> 
> Applied, thanks!
> 
> [1/1] PCI: dwc: Warn if the MSI ctrl doesn't have an associated platform IRQ in DT
>       commit: 571dd53fca80508de39cb2edc49a43be3ea5ae12
> 

Alex brought it to my attention offline that a vendor implementation may support
a single IRQ for all 256 MSIs. I checked the spec again and indeed they mention
the possibility in the Figure 3-24 of r4.30 of the DWC databook. It was not
mentioned in the wording anywhere, but the figure was explicit.

Hence, this patch is wrong. So I've dropped it now.

- Mani

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