Re: [PATCH v1 19/25] PCI: rcar Gen2: Request host bridge window resources

Bjorn Helgaas
2016-06-21T14:26:23Z

[+cc Valentine]

Hi Geert,

Thanks a lot for testing this, and sorry for the breakage.

On Tue, Jun 21, 2016 at 12:41:31PM +0200, Geert Uytterhoeven wrote:
> On Tue, Jun 7, 2016 at 1:07 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> > Request host bridge window resources so they appear in ioport_resource and
> > iomem_resource and are reflected in /proc/ioports and /proc/iomem.
> >
> > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> > ---
> > drivers/pci/host/pci-rcar-gen2.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
> > index 9980a4b..617a6b2 100644
> > --- a/drivers/pci/host/pci-rcar-gen2.c
> > +++ b/drivers/pci/host/pci-rcar-gen2.c
> > @@ -194,6 +194,7 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
> > struct rcar_pci_priv *priv = sys->private_data;
> > void __iomem *reg = priv->reg;
> > u32 val;
> > + int ret;
> >
> > pm_runtime_enable(priv->dev);
> > pm_runtime_get_sync(priv->dev);
> > @@ -275,6 +276,9 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
> > /* Add PCI resources */
> > pci_add_resource(&sys->resources, &priv->io_res);
> > pci_add_resource(&sys->resources, &priv->mem_res);
> > + ret = devm_request_pci_bus_resources(priv->dev, &sys->resources);
> > + if (ret < 0)
> > + return ret;
> >
> > /* Setup bus number based on platform device id / of bus-range */
> > sys->busnr = priv->busnr;
>
> This patch (commit 1bd019707b7c9249d34c5d348f1ef75eb4d83e89 in pci/next)
> broke PCI on r8a7791/koelsch. Dmesg differences are:
>
> pci-rcar-gen2 ee090000.pci: PCI: bus0 revision 11
> -pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00
> -pci_bus 0000:00: root bus resource [io 0xee080000-0xee0810ff]
> -pci_bus 0000:00: root bus resource [mem 0xee080000-0xee0810ff]

This is probably a result of this code in drivers/pci/host/pci-rcar-gen2.c:

/*
* The controller does not support/use port I/O,
* so setup a dummy port I/O region here.
*/
priv->io_res.start = priv->mem_res.start;
priv->io_res.end = priv->mem_res.end;
priv->io_res.flags = IORESOURCE_IO;

We try to avoid adding dummy regions like this, but maybe we missed
this one. I haven't found any email discussion about it yet, so I
don't know what the reason for this one is. Valentine, do you
remember?

Can you try the patch below (apply it before the 1bd019707b7c patch
that broke things)?

commit b64dc28f5f2b3afe47ee4a42fb79db84ec4227f8
Author: Bjorn Helgaas <bhelgaas@google.com>
Date: Tue Jun 21 09:19:34 2016 -0500

PCI: rcar: Drop gen2 dummy I/O port region

Previously we added a dummy I/O port region even though the R-Car
controller doesn't support PCI port I/O. This resulted in bogus root bus
resources like this:

pci_bus 0000:00: root bus resource [io 0xee080000-0xee0810ff]
pci_bus 0000:00: root bus resource [mem 0xee080000-0xee0810ff]

Drop the unused dummy I/O port region.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
index 9980a4b..53ae619 100644
--- a/drivers/pci/host/pci-rcar-gen2.c
+++ b/drivers/pci/host/pci-rcar-gen2.c
@@ -97,7 +97,6 @@
struct rcar_pci_priv {
struct device *dev;
void __iomem *reg;
- struct resource io_res;
struct resource mem_res;
struct resource *cfg_res;
unsigned busnr;
@@ -273,7 +272,6 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
rcar_pci_setup_errirq(priv);

/* Add PCI resources */
- pci_add_resource(&sys->resources, &priv->io_res);
pci_add_resource(&sys->resources, &priv->mem_res);

/* Setup bus number based on platform device id / of bus-range */
@@ -371,14 +369,6 @@ static int rcar_pci_probe(struct platform_device *pdev)
return -ENOMEM;

priv->mem_res = *mem_res;
- /*
- * The controller does not support/use port I/O,
- * so setup a dummy port I/O region here.
- */
- priv->io_res.start = priv->mem_res.start;
- priv->io_res.end = priv->mem_res.end;
- priv->io_res.flags = IORESOURCE_IO;
-
priv->cfg_res = cfg_res;

priv->irq = platform_get_irq(pdev, 0);