Re: [PATCH] PCI: Warn on possible RW1C corruption for sub-32 bit config writes

[Thierry Reding <treding@nvidia.com>]

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On Mon, Oct 31, 2016 at 04:39:02PM -0500, Bjorn Helgaas wrote:
> Hardware that supports only 32-bit config writes is not spec-compliant.
> For example, if software performs a 16-bit write, we must do a 32-bit read,
> merge in the 16 bits we intend to write, followed by a 32-bit write.  If
> the 16 bits we *don't* intend to write happen to have any RW1C (write-one-
> to-clear) bits set, we just inadvertently cleared something we shouldn't
> have.
> 
> Add a rate-limited warning when we do sub-32 bit config writes.  Remove
> similar probe-time warnings from some of the affected host bridge drivers.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
>  drivers/pci/access.c             |   17 +++++++++++++++--
>  drivers/pci/host/pcie-hisi.c     |    2 --
>  drivers/pci/host/pcie-rockchip.c |    3 ---
>  3 files changed, 15 insertions(+), 7 deletions(-)

Yeah, this is a good idea:

Acked-by: Thierry Reding <treding@nvidia.com>

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