Messages in this thread | | | From | Bjorn Helgaas <> | Date | Mon, 13 Aug 2012 21:25:55 -0700 | Subject | Re: [PATCH v3 00/32] provide interfaces to access PCIe capabilities registers |
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On Wed, Aug 1, 2012 at 8:54 AM, Jiang Liu <liuj97@gmail.com> wrote: > From: Jiang Liu <liuj97@gmail.com> > > As suggested by Bjorn Helgaas and Don Dutile in threads > http://www.spinics.net/lists/linux-pci/msg15663.html, we could improve access > to PCIe capabilities register in to way: > 1) cache content of PCIe Capabilities Register into struct pce_dev to avoid > repeatedly reading this register because it's read only. > 2) provide access functions for PCIe Capabilities registers to hide differences > among PCIe base specifications, so the caller don't need to handle those > differences. > > This patch set applies to > git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git pci-next
Would you mind rebasing this to v3.6-rc1? I think you posted this when my branch was still 3.5-based, and there are some upstream changes that cause minor conflicts here.
You currently have:
int pci_pcie_capability_change_word(struct pci_dev *dev, int pos, u16 set_bits, u16 clear_bits)
I think this is a bit awkward because the function name doesn't suggest *how* the word will be changed, and the clearing happens before the setting (opposite the parameter order). Something like:
int pci_pcie_capability_mask_and_set_word(..., u16 mask, u16 set) or int pci_pcie_capability_clear_and_set_word(..., u16 clear, u16 set)
would be more obvious. If you use "mask_and_set", I think the function should do "(val & mask) | set" with the complement being at the call site. If you use "clear_and_set", I think it's OK to do "(val & ~mask) | set" as in your current patch.
I know I suggested the "pci_pcie_capability_*" names, but they're getting a bit unwieldy, especially if we do "mask_and_set" or similar. There are already several "pcie_*" functions, so maybe we should drop the leading "pci_" from these and just have:
pcie_capability_read_word pcie_capability_write_word pcie_capability_mask_and_set_word
Bjorn
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