Re: [PATCH v4 3/5] PCI: axis: Add ARTPEC-8 PCIe controller driver

[Bjorn Helgaas]

On Thu, Jul 21, 2022 at 11:04:00AM +0200, Krzysztof Kozlowski wrote:
> On 20/07/2022 08:01, Wangseok Lee wrote:
> > Add support Axis, ARTPEC-8 SoC. ARTPEC-8 is the SoC platform of Axis
> > Communications. This is based on arm64 and support GEN4 & 2lane. This
> > PCIe controller is based on DesignWare Hardware core and uses DesignWare
> > core functions to implement the driver. "pcie-artpec6. c" supports artpec6
> > and artpec7 H/W. artpec8 can not be expanded because H/W configuration is
> > completely different from artpec6/7. PHY and sub controller are different.
> > 
> > Signed-off-by: Wangseok Lee <wangseok.lee@xxxxxxxxxxx>
> > Signed-off-by: Jaeho Cho <jaeho79.cho@xxxxxxxxxxx>
> > ---
> > v3->v4 :
> > -Remove unnecessary enum type
> > -Fix indentation
> > 
> 
> Thanks for the changes. This starts to look good, however I am not going
> to ack it. This is also not a strong NAK, as I would respect Bjorn and
> other maintainers decision.
> 
> I don't like the approach of creating only Artpec-8 specific driver.
> Samsung heavily reuses its block in all Exynos devices. Now it re-uses
> them for other designs as well. Therefore, even if merging with existing
> Exynos PCIe driver is not feasible (we had such discussions), I expect
> this to cover all Samsung Foundry PCIe devices. From all current designs
> up to future licensed blocks, including some new Samsung Exynos SoC. Or
> at least be ready for it.

I would certainly prefer fewer drivers but I don't know enough about
the underlying IP and the places it's integrated to to know what's
practical.  The only way I could figure that out would be by manually
comparing the drivers for similarity.  I assume/expect all driver
authors are doing that.

Bjorn