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SubjectRe: [PATCH 3/3] ahci: Document the loss of hotplug by new LPM policy
On Tue, May 24, 2022 at 12:05:08PM -0500, Mario Limonciello wrote:
> Per AHCI spec v1.3.1, "7.3 Native Hot Plug Support", once LPM is
> enabled hotplug support needs to be disabled.
>
> The LPM code always followed this and disabled the port when no
> drives were connected, but as more machines will be exposed to
> this code it might be an unexpected behavior to some users.
>
> Add a note to parameter documentation to explain the new behavior.
>
> Link: https://bugs.launchpad.net/bugs/1971576
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 9e6bd212004d..4dcd9a3ba4a5 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -279,6 +279,13 @@
> 3 => Medium power with Device Initiated PM enabled
> 4 => Minimum power
>
> + NOTE: Enabling LPM when no drive is connected will disable
> + the port which means hotplug will not work.
> +
> + If hotplug is an important use case, this can be modified

This has two overly long lines.

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