Re: [PATCH v2] PCI: add support for Immediate Readiness

[Felipe Balbi <felipe.balbi@linux.intel.com>]

Hi,

Felipe Balbi <felipe.balbi@linux.intel.com> writes:

> PCIe GEN4 defines, on section 7.5.1.1.4, a new bit on Status Register
> which tells us that:
>
> "Immediate Readiness – This optional bit, when Set, indicates the
> Function is guaranteed to be ready to successfully complete valid
> configuration accesses at any time following any reset that the host
> is capable of issuing Configuration Requests to this Function.
>
> When this bit is Set, for accesses to this Function, software is
> exempt from all requirements to delay configuration accesses following
> any type of reset, including but not limited to the timing
> requirements defined in Section 6.6.  How this guarantee is
> established is beyond the scope of this document.
>
> It is permitted that system software/firmware provide mechanisms that
> supersede the indication provided by this bit, however such
> software/firmware mechanisms are outside the scope of this
> specification."
>
> This means that all delays after a Conventional or Function Reset can
> be skipped.
>
> This patch reads such bit and caches its value in a flag inside struct
> pci_dev to be checked later if we should delay or can skip delays
> after a reset. While at that, also move the explicit msleep(100) call
> from pcie_flr() and pci_af_flr() to pci_dev_wait().
>
> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

A gentle reminder here

-- 
balbi