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.suthikulpanit@xxxxxxx wrote:
> > > From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> > >
> > > This patch implement set_msi_parent callback for PCI generic host controller.
> > >
> > > Cc: Bjorn Helgass <bhelgaas@xxxxxxxxxx>
> > > Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
> > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > > Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> > > ---
> > > 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 ?
What am I missing ?
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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