Re: [PATCH 2/2] ppc64: Add arch-specific pcie_get_speed_cap_mask

[Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>]

On Thu, Mar 14, 2013 at 02:45:47PM -0300, lucaskt@linux.vnet.ibm.com wrote:
> From: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com>
> 
> Betters support for gen2 speed detections on PCI buses on ppc64
> architectures.
> 
> Signed-off-by: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com>
> ---
>  arch/powerpc/platforms/pseries/pci.c |   32 ++++++++++++++++++++++++++++++++
>  1 files changed, 32 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
> index 0b580f4..58469fe 100644
> --- a/arch/powerpc/platforms/pseries/pci.c
> +++ b/arch/powerpc/platforms/pseries/pci.c
> @@ -24,6 +24,7 @@
>  #include <linux/kernel.h>
>  #include <linux/pci.h>
>  #include <linux/string.h>
> +#include <linux/device.h>
> 
>  #include <asm/eeh.h>
>  #include <asm/pci-bridge.h>
> @@ -108,3 +109,34 @@ static void fixup_winbond_82c105(struct pci_dev* dev)
>  }
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105,
>  			 fixup_winbond_82c105);
> +
> +int pcibios_get_speed_cap_mask(struct pci_dev *dev, u32 *mask)
> +{
> +	struct device_node *dn, *pdn;
> +	const uint32_t *pcie_link_speed_stats = NULL;
> +
> +	*mask = 0;
> +	dn = pci_bus_to_OF_node(dev->bus);
> +
> +	/* Find nearest ibm,pcie-link-speed-stats, walking up the device tree */
> +	for (pdn = dn; pdn != NULL; pdn = pdn->parent) {
> +		pcie_link_speed_stats = (const uint32_t *) of_get_property(pdn,
> +			"ibm,pcie-link-speed-stats", NULL);
> +		if (pcie_link_speed_stats != NULL)
> +			break;
> +	}
> +
> +	if (pcie_link_speed_stats == NULL) {
> +		dev_info(&dev->dev, "no ibm,pcie-link-speed-stats property\n");
> +		return -EINVAL;
> +	}
> +
> +	switch (pcie_link_speed_stats[0]) {
> +		case 0x02:
> +		*mask |= PCIE_SPEED_50;
> +		case 0x01:
> +		*mask |= PCIE_SPEED_25;
> +	}

I recall seeing this returns 0x00 as well. Maybe you should include both
0x00 and a default case and return EINVAL.

Regards.
Cascardo.

> +
> +	return 0;
> +}
> -- 
> 1.7.4.4
>