On Wed, 2013-03-20 at 02:24 -0300, Lucas Kannebley Tavares wrote:
Implementation of a architecture-specific pcibios_get_speed_cap_mask. This implementation detects bus capabilities based on OF ibm,pcie-link-speed-stats property.
The problem with your approach is that it's not a runtime detection...
If the pseries machine is compiled into the kernel binary, it will override pcibios_get_speed_cap_mask() using the device-tree, regardless of whether the machine is currently booted on a pseries machine or not.
This wouldn't be a big problem if the pseries pcibios_get_speed_cap_mask() was capable of doing a fallback to the generic one if the device-tree property is absent but that isn't the case.
I think what you need to do is:
- Make it so the generic one can be called by the override. This can look a bit tricky but it's better that way. One way to do it is to have the actual implementation be in a __pci_* variant called by the weak pcibios_* variant
- Move the powerpc on to arch/powerpc/kernel/pci-common.c and make it call a ppc_md.pcibios_get_speed_cap_mask(). If the hook is absent (NULL), make it call the generic one
- pseries can then populate the hook in ppc_md. with its custom variant.
Cheers, Ben.