Re: [PATCH v3 1/2] PCI: endpoint: pci-epf-test: Add support for capabilities

[Niklas Cassel <cassel@kernel.org>]

On Mon, Jan 20, 2025 at 09:14:15PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Jan 20, 2025 at 01:00:15PM +0100, Niklas Cassel wrote:
> > Hello Bjorn,
> > 
> > On Sat, Jan 18, 2025 at 02:34:21PM -0600, Bjorn Helgaas wrote:
> > > On Tue, Dec 03, 2024 at 07:38:53AM +0100, Niklas Cassel wrote:
> > > > The test BAR is on the EP side is allocated using pci_epf_alloc_space(),
> > > > which allocates the backing memory using dma_alloc_coherent(), which will
> > > > return zeroed memory regardless of __GFP_ZERO was set or not.
> > > 
> > > > +static void pci_epf_test_set_capabilities(struct pci_epf *epf)
> > > > +{
> > > > +	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> > > > +	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> > > > +	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> > > > +	struct pci_epc *epc = epf->epc;
> > > > +	u32 caps = 0;
> > > > +
> > > > +	if (epc->ops->align_addr)
> > > > +		caps |= CAP_UNALIGNED_ACCESS;
> > > > +
> > > > +	reg->caps = cpu_to_le32(caps);
> > > 
> > > "make C=2 drivers/pci/" complains about this:
> > > 
> > >   drivers/pci/endpoint/functions/pci-epf-test.c:756:19: warning: incorrect type in assignment (different base types)
> > >   drivers/pci/endpoint/functions/pci-epf-test.c:756:19:    expected unsigned int [usertype] caps
> > >   drivers/pci/endpoint/functions/pci-epf-test.c:756:19:    got restricted __le32 [usertype]
> > 
> > Yes, pci-epf-test is broken when it comes to endianness, as reported here:
> > https://lore.kernel.org/linux-pci/ZxYHoi4mv-4eg0TK@ryzen.lan/
> > 
> > 
> > Nice to see that sparse is complaining about it! :)
> > 
> > Mani said that he was going to work on it, but I guess that it fell through
> > the cracks.
> > 
> 
> It doesn't but I put it in the back burner due to other high priority issues to
> fix.

I know that feeling :)

Yeah, I know you have been very busy lately :)

Have a nice evening!


Kind regards,
Niklas