Re: [PATCH v2] PCI: al: Add Amazon Annapurna Labs PCIe host controller driver
From: Lorenzo Pieralisi
Date: Tue Mar 26 2019 - 11:58:49 EST
On Tue, Mar 26, 2019 at 01:24:41PM +0000, David Woodhouse wrote:
> On Tue, 2019-03-26 at 12:17 +0000, Lorenzo Pieralisi wrote:
> > [+Zhou, Gustavo]
> >
> > On Tue, Mar 26, 2019 at 12:00:55PM +0200, Jonathan Chocron wrote:
> > > Adding support for Amazon's Annapurna Labs PCIe driver.
> > > The HW controller is based on DesignWare's IP.
> > >
> > > The HW doesn't support accessing the Root Port's config space via
> > > ECAM, so we obtain its base address via an AMZN0001 device.
> > >
> > > Furthermore, the DesignWare PCIe controller doesn't filter out
> > > config transactions sent to devices 1 and up on its bus, so they
> > > are filtered by the driver.
> > > All subordinate buses do support ECAM access.
> > >
> > > Implementing specific PCI config access functions involves:
> > > - Adding an init function to obtain the Root Port's base address
> > > from an AMZN0001 device.
> > > - Adding a new entry in the mcfg quirk array
> > >
> > > Co-developed-by: Vladimir Aerov <vaerov@xxxxxxxxxx>
> > > Signed-off-by: Jonathan Chocron <jonnyc@xxxxxxxxxx>
> > > Signed-off-by: Vladimir Aerov <vaerov@xxxxxxxxxx>
> > > Reviewed-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> > > Reviewed-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
> >
> > Review tags should be given on public mailing lists for public
> > review and I have not seen them (they were already there in v1) so
> > you should drop them.
>
> We did that internally. You really don't want me telling engineers to
> post to the list *first* without running things by me to get the basics
> right. Not to start with, at least.
Hi David,
I am obviously in favour of internal review and I do not question it was
carried out internally, I just kindly ask developers to drop review tags
given internally when going to public mailing lists - I understand it is
churn for you but I prefer them to be given explicitly.
Thanks !
Lorenzo
> Reviewed-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
>
>
> > > Changes from v1:
> > > - Fix commit message comments (incl. using AMZN0001
> > > instead of PNP0C02)
> > > - Use the usual multi-line comment style
> > >
> > > MAINTAINERS | 6 +++
> > > drivers/acpi/pci_mcfg.c | 12 +++++
> > > drivers/pci/controller/dwc/Makefile | 1 +
> > > drivers/pci/controller/dwc/pcie-al.c | 93 ++++++++++++++++++++++++++++++++++++
> > > include/linux/pci-ecam.h | 1 +
> > > 5 files changed, 113 insertions(+)
> > > create mode 100644 drivers/pci/controller/dwc/pcie-al.c
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 32d444476a90..7a17017f9f82 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -11769,6 +11769,12 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/
> > > S: Supported
> > > F: drivers/pci/controller/
> > >
> > > +PCIE DRIVER FOR ANNAPURNA LABS
> > > +M: Jonathan Chocron <jonnyc@xxxxxxxxxx>
> > > +L: linux-pci@xxxxxxxxxxxxxxx
> > > +S: Maintained
> > > +F: drivers/pci/controller/dwc/pcie-al.c
> >
> > I do not think we need a maintainer file for that see below, and
> > actually this quirk should be handled by DWC maintainers since it is a
> > DWC quirk, not a platform one.
>
> Many of the others already have this, it seems.
>
> It's also fine to drop it, and include it when we add the rest of the
> Alpine SOC support and a MAINTAINERS entry for that.
>