Re: [PATCH v2 1/2] PCI: endpoint: pci-epf-test: Add support for capabilities

Manivannan Sadhasivam
2024-12-08T12:42:12Z

On Tue, Dec 03, 2024 at 05:43:10AM +0100, Niklas Cassel wrote:
> Hello Mani,
>
> On Sat, Nov 30, 2024 at 01:42:45PM +0530, Manivannan Sadhasivam wrote:
> > >
> > > struct pci_epf_test {
> > > @@ -74,6 +76,7 @@ struct pci_epf_test_reg {
> > > u32 irq_type;
> > > u32 irq_number;
> > > u32 flags;
> > > + u32 caps;
> >
> > Can we rename the 'magic' register? It is not used since the beginning and I
> > don't know if we will ever have a usecase for it.
>
> It is actually used!
>
> When doing PCITEST_BAR (pci_endpoint_test_bar()),
> and barno == test->test_reg_bar, we are only filling the first 4 bytes,
> rather than filling the whole BAR:
> https://github.com/torvalds/linux/blob/v6.13-rc1/drivers/misc/pci_endpoint_test.c#L293-L294
>
> These first 4 bytes are stored in the magic register.
>

heh, not so evident... thanks anyway.

> I do agree that the magic register name is slightly misleading, but that
> seems completely unrelated to this patch.
>
> If you can come up with a better name, send a patch and you shall have
> my Reviewed-by tag :)
>

How about 'scratchpad'?

- Mani

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