Re: [PATCH v5 5/5] Driver: VMBus: Add device tree support

Saurabh Singh Sengar
2023-02-17T13:27:14Z

On Mon, Feb 13, 2023 at 03:24:39AM -0800, Saurabh Singh Sengar wrote:
> On Fri, Feb 10, 2023 at 04:37:28PM -0600, Rob Herring wrote:
> > On Thu, Feb 9, 2023 at 11:46 AM Saurabh Singh Sengar
> > <ssengar@linux.microsoft.com> wrote:
> > >
> > > On Thu, Feb 09, 2023 at 09:50:31AM -0600, Rob Herring wrote:
> > > > On Thu, Feb 9, 2023 at 6:15 AM Saurabh Sengar
> > > > <ssengar@linux.microsoft.com> wrote:
> > > > >
> > > > > Update the driver to support device tree boot as well along with ACPI.
> > > >
> > > > Devicetree
> >
> > [...]
> >
> > > > > + for_each_of_range(&parser, &range) {
> > > > > + struct resource *res;
> > > > > +
> > > > > + res = kzalloc(sizeof(*res), GFP_ATOMIC);
> > > > > + if (!res)
> > > > > + return -ENOMEM;
> > > > > +
> > > > > + res->name = "hyperv mmio";
> > > > > + res->flags = IORESOURCE_MEM | IORESOURCE_MEM_64;
> > > > > + res->start = range.pci_addr;
> > > >
> > > > This is not PCI. It's a union, so use 'bus_addr' instead.
> > > >
> > > > But wait, resources and IORESOURCE_MEM are *CPU* addresses. You need
> > > > cpu_addr here. Your DT happens to do 1:1 addresses so it happens to
> > > > work either way.
> > >
> > > bus_addr works for us, will send V6
> >
> > Sigh. bus_addr may work, but is wrong as I explained.
> >
> > And you've already sent v6... Please slow down your pace with sending
> > new versions. 4 versions in a week is too much. Give others time to
> > comment and me to respond to discussions. Like a week...
>
> I apologize if my actions may have come across as overly hasty. I will make
> sure to allow for more time between submissions in the future, to ensure that
> everyone has an adequate opportunity to review and provide feedback.
>
> Regarding the use of bus_addr instead of cpu_addr, I found that cpu_addr was
> populating as OF_BAD_ADDR while bus_addr was populating correctly. I think
> this is because I should be defining a empty ranges property in parent node
> for indicating 1:1 mapping between parent and child.
>
> But once I add empty ranges in property I get other warnings by dt_binding_check
> tool. After fixing all I am able to come up with below device tree example, please
> let me know if there is anything to be corrected. If this is good I will send
> the next version (offcource after a week :)) using cpu_addr.
>
> soc {
> #address-cells = <2>;
> #size-cells = <1>;
> bus {
> compatible = "simple-bus";
> #address-cells = <2>;
> #size-cells = <1>;
> ranges;
>
> vmbus@ff0000000 {
> compatible = "microsoft,vmbus";
> #address-cells = <2>;
> #size-cells = <1>;
> ranges = <0x0f 0xf0000000 0x0f 0xf0000000 0x10000000>;
> };
> };
> };
>
> >

Rob,

If you find the above changes satisfactory, please do let me know so that
I can send the updated version.

As far as I am aware, all the pending comments and issues have been addressed
in this series. However, if there are any remaining concerns or feedback that
require attention, please let me know.

- Saurabh

> > Rob