Re: [PATCH v2 2/2] PCI: tegra: apply relaxed ordering fixup only on Tegra

[Thierry Reding <thierry.reding@gmail.com>]

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On Thu, Dec 18, 2014 at 08:11:43PM +0100, Lucas Stach wrote:
> The fixup to enable relaxed ordering on all PCI devices was
> executed unconditionally if the Tegra PCI host driver was
> built into the kernel. This doesn't play nice with a
> multiplatform kernel executed on other platforms which
> may not need this fixup.
> 
> Make sure to only apply the fixup if the root port is
> a Tegra.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> v2:
> - split out PCI hierarchy walk
> - separate code from data by moving PCI IDs into own structure
> ---
>  drivers/pci/host/pci-tegra.c | 34 +++++++++++++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index 333a57afacc4..b77f417e1a3c 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -635,10 +635,42 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x0bf1, tegra_pcie_fixup_class);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x0e1c, tegra_pcie_fixup_class);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x0e1d, tegra_pcie_fixup_class);
>  
> +static const struct pci_device_id tegra_rootport_ids[] = {
> +	{
> +		/* Tegra20 4 lane root port */
> +		.vendor = PCI_VENDOR_ID_NVIDIA, .device = 0x0bf0,
> +		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID
> +	}, {
> +		/* Tegra20 2 lane root port */
> +		.vendor = PCI_VENDOR_ID_NVIDIA, .device = 0x0bf1,
> +		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID

The number of lanes is configurable, so I'm not sure exactly what this
comment is supposed to indicate. Are you saying that port 0 has 0x0bf0
and port 1 has 0x0bf1 as device IDs.

> +	}, {
> +		/* Tegra30 4 lane root port */
> +		.vendor = PCI_VENDOR_ID_NVIDIA, .device = 0x0e1c,
> +		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID
> +	}, {
> +		/* Tegra30 2 lane root port */
> +		.vendor = PCI_VENDOR_ID_NVIDIA, .device = 0x0e1d,
> +		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID

Tegra30 has three ports, so does this second entry (0x0e1d) apply to
ports 1 and 2, whereas the previous entry (0x0e1c) applies only to port
0?

> +	}, {
> +		/* Tegra124 4 lane root port */
> +		.vendor = PCI_VENDOR_ID_NVIDIA, .device = 0x0e12,
> +		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID
> +	}, {
> +		/* Tegra124 1 lane root port */
> +		.vendor = PCI_VENDOR_ID_NVIDIA, .device = 0x0e13,
> +		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID

Or perhaps what this signifies is that the first port is actually a
different device because it supports up to 4 lanes, whereas the others
support up to 2 lanes (or only 1 on Tegra124)? In that case:

Acked-by: Thierry Reding <treding@nvidia.com>

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