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SubjectRe: [PATCH v2 1/3] dt-bindings: PCI: brcmstb: Add two optional props
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On 11/04/2023 18:59, Jim Quinlan wrote:
> Regarding "brcm,enable-l1ss":
>
> The Broadcom STB/CM PCIe HW -- a core that is also used by RPi SOCs --
> requires the driver probe() to deliberately place the HW one of three
> CLKREQ# modes:
>
> (a) CLKREQ# driven by the RC unconditionally
> (b) CLKREQ# driven by the EP for ASPM L0s, L1
> (c) Bidirectional CLKREQ#, as used for L1 Substates (L1SS).
>
> The HW+driver can tell the difference between downstream devices that
> need (a) and (b), but does not know when to configure (c). Further, the
> HW may cause a CPU abort on boot if guesses wrong regarding the need for
> (c). So we introduce the boolean "brcm,enable-l1ss" property to indicate
> that (c) is desired. Setting this property only makes sense when the
> downstream device is L1SS-capable and the OS is configured to activate
> this mode (e.g. policy==superpowersave).
>
> This property is already present in the Raspian version of Linux, but the
> upstream driver implementaion that will follow adds more details and

typo, implementation

> discerns between (a) and (b).
>
> Regarding "brcm,completion-timeout-us"
>
> Our HW will cause a CPU abort if the L1SS exit time is longer than the
> PCIe transaction completion abort timeout. We've been asked to make this
> configurable, so we are introducing "brcm,completion-timeout-us".
>
> Signed-off-by: Jim Quinlan <jim2101024@gmail.com>

What happened here? Where is the changelog?

Best regards,
Krzysztof

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