On Thu, Nov 13, 2014 at 03:22:43PM +0000, Lorenzo Pieralisi wrote:
> On Tue, Nov 11, 2014 at 11:52:27AM +0000, Liviu Dudau wrote:
> > On Tue, Nov 11, 2014 at 11:24:24AM +0000, Will Deacon wrote:
> > > Hi Suravee,
> > >
> > > On Mon, Nov 10, 2014 at 07:24:40PM +0000, suravee.suthikulpa...@amd.com
> > > wrote:
> > > > From: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
> > > >
> > > > This patch implement set_msi_parent callback for PCI generic host
> > > > controller.
> > > >
> > > > Cc: Bjorn Helgass <bhelg...@google.com>
> > > > Cc: Liviu Dudau <liviu.du...@arm.com>
> > > > Cc: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
> > > > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
> > > > ---
> > > > drivers/pci/host/pci-host-generic.c | 14 ++++++++++++++
> > > > 1 file changed, 14 insertions(+)
> > > >
> > > > diff --git a/drivers/pci/host/pci-host-generic.c
> > > > b/drivers/pci/host/pci-host-generic.c
> > > > index 036ab1b..f9bb97a 100644
> > > > --- a/drivers/pci/host/pci-host-generic.c
> > > > +++ b/drivers/pci/host/pci-host-generic.c
> > > > @@ -42,6 +42,7 @@ struct gen_pci {
> > > > struct pci_host_bridge host;
> > > > struct gen_pci_cfg_windows cfg;
> > > > struct list_head resources;
> > > > + struct msi_chip *mchip;
> > > > };
> > > >
> > > > #ifdef CONFIG_ARM
> > > > @@ -128,9 +129,19 @@ static int gen_pci_config_write(struct pci_bus
> > > > *bus, unsigned int devfn,
> > > > return PCIBIOS_SUCCESSFUL;
> > > > }
> > > >
> > > > +static int gen_pci_set_msi_parent(struct pci_bus *bus)
> > > > +{
> > > > + struct gen_pci *pci = bus_to_gen_pci(bus);
> > > > +
> > > > + bus->msi = pci->mchip;
> > > > +
> > > > + return PCIBIOS_SUCCESSFUL;
> > > > +}
> > >
> > > I don't think this makes much sense a host controller callback. Why can't
> > > bus->msi be set in generic code?
> >
> > Because of the current way in which a bus gets created and them immediately
> > used for
> > scanning devices if you use pci_scan_root_bus(). Alternative is to use
> > pci_create_root_bus()
> > and increase your code size with the body of pci_scan_root_bus().
> >
> > Solution is to have pci_host_bridge holding the msi_chip pointer and that
> > gets created
> > before root bus, with pci_scan_root_bus() now having all the info needed to
> > do successful
> > setup of scanned devices.
>
> Why can't we add a hook like pci_bus_assign_domain_nr(), say:
>
> pci_bus_msi_init()
>
> in pci_create_root_bus() that does what Suravee wants in a generic way ?
Because even pci_bus_assign_domain_nr() was not really generic until your
patches (small steps, etc).
We need a patch that proposes that and we can discuss it.
>
> What am I missing ?
Other than the fact that we need to sort out the initialisation order of all
these components, nothing I guess.
Best regards,
Liviu
>
> Lorenzo
>
> >
> > Best regards,
> > Liviu
> >
> > >
> > > > static struct pci_ops gen_pci_ops = {
> > > > .read = gen_pci_config_read,
> > > > .write = gen_pci_config_write,
> > > > + .set_msi_parent = gen_pci_set_msi_parent,
> > > > };
> > > >
> > > > static const struct of_device_id gen_pci_of_match[] = {
> > > > @@ -313,6 +324,9 @@ static int gen_pci_probe(struct platform_device
> > > > *pdev)
> > > > return err;
> > > > }
> > > >
> > > > + pci->mchip = of_pci_find_msi_chip_by_node(of_parse_phandle(np,
> > > > + "msi-parent", 0));
> > >
> > > This bit should be in the generic of_pci.c code and not duplicated for
> > > each host controller.
> > >
> > > Will
> > >
> >
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
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