Since 2.6.36 (253d2e5498), we've disabled MEM & IO decoding while we size
BARs (except for host bridge devices). These patches tweak this in two
ways:
1) We only kept decoding disabled while sizing the low-order dword
of 64-bit BARs. I think we should keep it disabled while we do the
high-order dword also.
2) I think we should also disable decoding while updating 64-bit BARs,
e.g., when we move a device into an aperture of an upstream bridge. I'm
only proposing to disable decoding for 64-bit BAR updates because 32-bit
ones can be done atomically, while 64-bit updates require two writes and
the half-written state is a potential problem.
I'm considering these changes for the 3.6 merge window, which is
approaching fast, so let me know if you see issues with either of these.
---
Bjorn Helgaas (2):
PCI: leave MEM and IO decoding disabled during 64-bit BAR sizing, too
PCI: disable MEM decoding while updating 64-bit MEM BARs
drivers/pci/probe.c | 6 +++---
drivers/pci/setup-res.c | 18 ++++++++++++++++++
2 files changed, 21 insertions(+), 3 deletions(-)
--
Bjorn
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