On Fri, May 13, 2022 at 12:28:40PM +0300, Dmitry Baryshkov wrote:
> On Fri, 13 May 2022 at 11:58, Johan Hovold <johan@xxxxxxxxxx> wrote:
> >
> > On Thu, May 12, 2022 at 01:45:35PM +0300, Dmitry Baryshkov wrote:
> > > I have replied with my Tested-by to the patch at [2], which has landed
> > > in the linux-next as the commit 20f1bfb8dd62 ("PCI: qcom:
> > > Add support for handling MSIs from 8 endpoints"). However lately I
> > > noticed that during the tests I still had 'pcie_pme=nomsi', so the
> > > device was not forced to use higher MSI vectors.
> > >
> > > After removing this option I noticed that hight MSI vectors are not
> > > delivered on tested platforms. After additional research I stumbled upon
> > > a patch in msm-4.14 ([1]), which describes that each group of MSI
> > > vectors is mapped to the separate interrupt. Implement corresponding
> > > mapping.
> > >
> > > The first patch in the series is a revert of [2] (landed in pci-next).
> > > Either both patches should be applied or both should be dropped.
> > >
> > > Patchseries dependecies: [3] (for the schema change).
> > >
> > > Changes since v7:
> > > - Move code back to the dwc core driver (as required by Rob),
> > > - Change dt schema to require either a single "msi" interrupt or an
> > > array of "msi0", "msi1", ... "msi7" IRQs. Disallow specifying a
> > > part of the array (the DT should specify the exact amount of MSI IRQs
> > > allowing fallback to a single "msi" IRQ),
> >
> > Why this new constraint?
> >
> > I've been using your v7 with an sc8280xp which only has four IRQs (and
> > hence 128 MSIs).
> >
> > Looks like this version of the series would not allow that anymore.
>
> It allows it, provided that you set pp->num_vectors correctly (to 128
> in your case).
> The main idea was to disallow mistakes in the platform configuration.
> If the platform says that it supports 256 vectors (and 8 groups),
> there must be 8 groups. Or a single backwards-compatible group.
But you also added
+ - properties:
+ interrupts:
+ minItems: 8
+ interrupt-names:
+ minItems: 8
+ items:
+ - const: msi0
+ - const: msi1
+ - const: msi2
+ - const: msi3
+ - const: msi4
+ - const: msi5
+ - const: msi6
+ - const: msi7
which means that I can no longer describe the four interrupts in DT.
I didn't check the implementation, but it seems you should derive the
number of MSIs based on the devicetree as I guess you did in v7.
Johan
