On Mon, Aug 16, 2021 at 8:36 AM Mauro Carvalho Chehab
<mchehab+huawei@xxxxxxxxxx> wrote:
>
> Em Mon, 16 Aug 2021 10:42:52 +0200
> Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> escreveu:
>
> > Em Sat, 14 Aug 2021 12:32:56 -0500
> > Rob Herring <robh@xxxxxxxxxx> escreveu:
> >
> > > On Fri, Aug 13, 2021 at 12:19 PM Mauro Carvalho Chehab
> > > <mchehab+huawei@xxxxxxxxxx> wrote:
> > > >
> > > > Em Fri, 13 Aug 2021 11:02:57 -0500
> > > > Rob Herring <robh@xxxxxxxxxx> escreveu:
> > > >
> > > > > When a DT contains PCI child bus nodes, lookup of the MSI domain on PCI
> > > > > buses fails resulting in the following warnings:
> > > > >
> > > > > WARNING: CPU: 4 PID: 7 at include/linux/msi.h:256 __pci_enable_msi_range+0x398/0x59c
> > > > >
> > > > > The issue is that pci_host_bridge_of_msi_domain() will check the DT node of
> > > > > the passed in bus even if it's not the host bridge's bus. Based on the
> > > > > name of the function, that's clearly not what we want. Fix this by
> > > > > walking the bus parents to the root bus.
> > > > >
> > > > > Reported-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> > > > > Cc: Marc Zyngier <maz@xxxxxxxxxx>
> > > > > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > > > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > > > > Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> > > > > ---
> > > > > Compile tested only. Mauro, Can you see if this fixes your issue.
> > > > >
> > > > > drivers/pci/of.c | 4 ++++
> > > > > 1 file changed, 4 insertions(+)
> > > > >
> > > > > diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> > > > > index a143b02b2dcd..ea70aede054c 100644
> > > > > --- a/drivers/pci/of.c
> > > > > +++ b/drivers/pci/of.c
> > > > > @@ -84,6 +84,10 @@ struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
> > > > > if (!bus->dev.of_node)
> > > > > return NULL;
> > > > >
> > > > > + /* Find the host bridge bus */
> > > > > + while (!pci_is_root_bus(bus))
> > > > > + bus = bus->parent;
> > > > > +
> > > > > /* Start looking for a phandle to an MSI controller. */
> > > > > d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
> > > > > if (d)
> > > >
> > > > Nope, it didn't solve the issue.
> > >
> > > Can you try adding some prints of the domain, pci dev, and DT node to
> > > pci_set_bus_msi_domain(). Comparing those when having child nodes or
> > > not would be helpful.
> >
> > Debug patch enclosed.
> >
> > This is what happens when msi-parent is at /soc/pcie@f4000000/pcie@0,0:
> >
> > [ 4.305247] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: ffff000104a2f6c0
> > [ 4.442212] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: ffff000104a2f6c0
> > [ 4.688145] pci_bus 0000:03: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0/pcie@1,0: IRQ domain: ffff000104a2f6c0
> > [ 4.800613] pci_bus 0000:04: pci_set_bus_msi_domain: of_node (null): IRQ domain: ffff000104a2f6c0
> > [ 4.856254] pci_bus 0000:05: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0/pcie@5,0: IRQ domain: ffff000104a2f6c0
> > [ 4.922117] pci_bus 0000:06: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0/pcie@7,0: IRQ domain: ffff000104a2f6c0
> > [ 5.032708] pci_bus 0000:07: pci_set_bus_msi_domain: of_node (null): IRQ domain: ffff000104a2f6c0
> >
> > And this is what happens when msi-parent is at /soc/pcie@f4000000
> > (either with or without your patch applied):
> >
> > [ 4.120328] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.214541] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.226054] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.478858] pci_bus 0000:03: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0/pcie@1,0: IRQ domain: 0000000000000000
> > [ 4.491218] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.502793] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.588196] pci_bus 0000:04: pci_set_bus_msi_domain: of_node (null): IRQ domain: 0000000000000000
> > [ 4.597161] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.608747] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.658892] pci_bus 0000:05: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0/pcie@5,0: IRQ domain: 0000000000000000
> > [ 4.671241] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.682869] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.732938] pci_bus 0000:06: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0/pcie@7,0: IRQ domain: 0000000000000000
> > [ 4.745305] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.756880] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.850363] pci_bus 0000:07: pci_set_bus_msi_domain: of_node (null): IRQ domain: 0000000000000000
> > [ 4.859322] pci_bus 0000:02: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0/pcie@0,0: IRQ domain: 0000000000000000
> > [ 4.870895] pci_bus 0000:01: pci_set_bus_msi_domain: of_node /soc/pcie@f4000000/pcie@0,0: IRQ domain: 0000000000000000
> >
> > Btw, despite lspci works on both cases, the Ethernet adapter stops
> > working when msi-parent is at /soc/pcie@f4000000. I didn't notice it
> > before, as (up to last week) I was using WiFi to connect to this board.
> >
> > Thanks,
> > Mauro
> >
> > [PATCH] PCI: probe: Add a debug printk at pci_set_bus_msi_domain
> >
> > That helps to discover problems when trying to get the MSI IRQ
> > domain.
> >
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> >
> > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> > index c5dfc1afb1d3..f73bd81922b3 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -866,6 +866,8 @@ static void pci_set_bus_msi_domain(struct pci_bus *bus)
> > for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) {
> > if (b->self)
> > d = dev_get_msi_domain(&b->self->dev);
> > + dev_dbg(&b->dev, "%s: of_node %pOF: IRQ domain: %px\n",
> > + __func__, b->dev.of_node, d);
> > }
> >
> > if (!d)
> >
>
> I added a lot of other debug stuff (see attached).
>
> When msi-parent is at:
>
> pcie@f4000000 {
> msi-parent = <&its_pcie>;
> };
Are you sure the IRQ domain got created for its_pcie? From your dts
changes, you have a GICv3-ITS without a GICv3. I don't think that's
right.
The DWC driver will skip setting up it's own MSI controller if
'msi-parent' is present in the DWC node. So if you move it out of that
node, then the DWC MSI controller will be found and used. Try removing
'msi-parent' and the its_pcie node.
Rob
