Re: [PATCH RFC NOT TESTED 0/2] PCI: artpec6: Try to clean up artpec6_pcie_cpu_addr_fixup()

[Niklas Cassel]

On Wed, Mar 05, 2025 at 12:18:56PM +0100, Niklas Cassel wrote:
> Hello Frank, all,
> 
> On Tue, Mar 04, 2025 at 12:49:34PM -0500, Frank Li wrote:
> > This patches basic on
> > https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@xxxxxxx/
> > 
> > I have not hardware to test and there are not axis,artpec7-pcie in kernel
> > tree.
> 
> If you do a simple:
> $ git grep artpec7
> 
> You will see that there are just two drivers that support this SoC:
> drivers/pci/controller/dwc/pcie-artpec6.c
> drivers/crypto/axis/artpec6_crypto.c
> and their matching DT bindings:
> Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt
> Documentation/devicetree/bindings/crypto/artpec6-crypto.txt
> 
> I think that at some point in the there was an intent to upstream support
> for the ARTPEC-7 SoC, but now many years later, that hasn't happened,
> as there is not even a artpec7 dtsi.
> 
> I think the nicest thing to the community is to drop artpec7 support from
> these two drivers, and deprecate the artpec7 compatibles in the DT bindings,
> as it is obviously making your life harder when trying to do improvements.
> 
> 
> > 
> > Look for driver owner, who help test this and start move forward to remove
> > cpu_addr_fixup() work.
> 
> While I'm the original author of this PCIe driver, I do no longer have
> access to the hardware and documentation, so I cannot test.
> 
> For anyone interested in the cleanup Frank is doing, see:
> https://lore.kernel.org/linux-pci/Z8d96Qbggv117LlO@lizhi-Precision-Tower-5810/T/#m0ff14edaf871293ba16acd85e7942adacb603c6c
> 
> Looking at your cover-letter for the series above,
> creating a simple-bus with:
> ranges = <0x0 0xc0000000 0x20000000>
> 
> and handling that in PCIe DWC common code does look nicer compared to
> having a .cpu_addr_fixup() callback in each PCIe DWC glue driver.
> 
> Hopefully someone with access to the hardware can test your series +
> this RFC.

Oh, and you should probably send a similar RFC for:
drivers/pci/controller/dwc/pci-dra7xx.c
drivers/pci/controller/dwc/pcie-intel-gw.c
drivers/pci/controller/dwc/pcie-visconti.c

which all make use of the .cpu_addr_fixup() callback.
(IIRC dra7xx was the first driver that introduced this callback.)


Kind regards,
Niklas