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 Fri, Jan 09, 2015 at 12:45:18PM +0100, Lucas Stach wrote:
> Am Freitag, den 09.01.2015, 12:32 +0100 schrieb Thierry Reding:
> > 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.
> > 
> 
> No, the device ID of the root port is dependent on the number of lanes
> configured for the specific port. So if you have a 4x1 configuration you
> will get to see a single device with ID 0x0bf0, in a 2x2 configuration
> you will see 2 devices with ID 0x0bf1.

Okay, that's interesting to know. My ack remains valid in that case:

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

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