On Fri, Aug 04, 2017 at 04:39:36PM +0800, Honghui Zhang wrote:
> On Thu, 2017-08-03 at 17:42 -0500, Bjorn Helgaas wrote:
>
>
> ......
> > > +}
> > > +
> > > +static struct mtk_pcie_port *mtk_pcie_find_port(struct mtk_pcie *pcie,
> > > + struct pci_bus *bus, int devfn)
> > > +{
> > > + struct pci_dev *dev;
> > > + struct pci_bus *pbus;
> > > + struct mtk_pcie_port *port, *tmp;
> > > +
> > > + list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
> > > + if (bus->number == 0 && port->index == PCI_SLOT(devfn)) {
> > > + return port;
> > > + } else if (bus->number != 0) {
> > > + pbus = bus;
> > > + do {
> > > + dev = pbus->self;
> > > + if (port->index == PCI_SLOT(dev->devfn))
> > > + return port;
> > > + pbus = dev->bus;
> > > + } while (dev->bus->number != 0);
> > > + }
> > > + }
> > > +
> > > + return NULL;
> >
> > You should be able to use sysdata to avoid searching the list.
> > See drivers/pci/host/pci-aardvark.c, for example.
> >
>
> I could put the mtk_pcie * in sysdata, but still need to searching the
> list to get the mtk_pcie_port *, how about:
>
> list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
> if (port->index == PCI_SLOT(devfn))
> return port;
> }
No. Other drivers don't need to search the list. Please take a look
at them and see how they solve this problem. I don't think your
hardware is fundamentally different in a way that means you need to
search when the others don't.
> > > + * Enable rc internal reset.
> > > + * The reset will work when the link is from link up to link down.
> >
> > ? That sentence doesn't parse for me.
>
> What about:
>
> /*
> * Enable PCIe link down reset, if link status changed from link up to
> * link down, this will reset MAC control registers and configuration
> * space.
> */
That at least parses as a sentence.
> > > + port->irq_domain = irq_domain_add_linear(pcie_intc_node, INTX_NUM,
> > > + &intx_domain_ops, port);
> >
> > I think there's an issue here with a 4-element IRQ domain and the
> > hwirq numbers 1-4 from the of_irq_parse_and_map_pci() path, so INTD
> > may not work correctly.
> >
> > See
> > http://lkml.kernel.org/r/20170801212931.GA26498@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > and related discussion.
>
> Sorry, I did not get this,
> I do some test with an intel E350T4 PCIe NICs, it's a x1 lane
> multi-function device.
> What I got from the log is below:
> ->of_irq_parse_and_map_pci
> ->of_irq_parse_pci
> ->irq_create_of_mapping
> ->irq_create_fwspec_mapping
> ->irq_domain_translate
> which will go through
> d->ops->translate #the hwirq really start from 0
>
> And I tested every NIC port of the Intel E350T4 with tftp transfer data,
> seems all are OK with this code.
OK. I don't know what d->ops->translate is involved here, but if it
works, I guess this is OK for now. We're trying to clean this up and
make it consistent across all the drivers. Many of them allocate a
5-element IRQ domain, some make a 4-element domain, and on some of
them INTD doesn't work. It's a mess.
Bjorn
