[RFC PATCH 0/3] PCI: imx6: fixup for add-in card IRQ mismapping

[Tim Harvey]

On Thu, Feb 27, 2014 at 5:50 PM, Jingoo Han <jg1.han at samsung.com> wrote:
>
> On Friday, February 28, 2014 10:20 AM, Tim Harvey wrote:
> >
> > An add-in card used on the Ventana IMX6 SoC based family of boards has a
> > TI XIO2001 PCIe-to-PCI bridge where the INTA/B/C/D mappings between the
> > bridge and the four mini-PCI slots are swapped (INTD/C/B/A).
>
> (+cc Marek Vasut, Pratyush Anand, Kishon Vijay Abraham I, Mohit KUMAR DCG)
>
> This problem happens from the 'Board', not a 'SoC'.
> 'TI XIO2001 PCIe-to-PCI bridge' is not a 'SoC'.
> 'pci-imx6.c' is the driver for 'IMX6 PCI IP', not for 'IMX6 SoC based
> board'. Isn't it?

Jingoo,

Correct, this is an issue in the way the XIO2001 was hooked up to the
PCI slots, so it should be viewed as a board issue.

>
> Then, the workaround code for board problem should NOT be
> included to './drivers/pci/host/' side.

I would agree, but to overcome this sort of interrupt mapping issue
one would need to either implement a custom swizzle or perhaps a
custom map_irq and both of those are hooked into the pcie driver core.
 Do you have any suggestions on where/how I would better hook into
those?

>
> Also, please add the following members to CC list. They will give
> important comments.
>
> : Marek Vasut, Pratyush Anand, Kishon Vijay Abraham I, Mohit KUMAR DCG
>
> Best regards,
> Jingoo Han

Thanks,

Tim

>
> >
> > This series adds legacy PCI interrupt mapping to support PCI bridges on
> > IMX6 PCIe host controllers, adds the ability to use a host-specific
> > custom swizzle function, then uses that to fix the IRQ mapping.
> >
> > I'm hoping this is the right way to perform such a workaround - please provide
> > feedback if not.  Patch1 will likely collide with the owrk Lucas is doing
> > with device-tree bindings and MSI support.  I'm happy to re-base if/when
> > needed.
> >
> > Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> > Cc: Bjorn Helgaas <bhelgaas at google.com>
> > Cc: Richard Zhu <r65037 at freescale.com>
> > Cc: Shawn Guo <shawn.guo at linaro.org>
> > Cc: Lucas Stach <l.stach at pengutronix.de>
> > Cc: Sean Cross <xobs at kosagi.com>
> > Cc: Jingoo Han <jg1.han at samsung.com>
> > ---
> > Tim Harvey (3):
> >   PCI: designware: add legacy PCI interrupt mapping
> >   PCI: designware: add ability for custom swizzle
> >   PCI: imx6: ventana: fixup for IRQ mismapping
> >
> >  arch/arm/boot/dts/imx6qdl.dtsi     |  2 +-
> >  drivers/pci/host/pci-exynos.c      |  7 ++++--
> >  drivers/pci/host/pci-imx6.c        | 47 ++++++++++++++++++++++++++++++++++----
> >  drivers/pci/host/pcie-designware.c | 11 ++++++++-
> >  drivers/pci/host/pcie-designware.h |  3 ++-
> >  include/linux/pci_ids.h            |  1 +
> >  6 files changed, 62 insertions(+), 9 deletions(-)
> >
> > --
> > 1.8.3.2
>