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References: <20220315190228.1503866-1-wse@tuxedocomputers.com> <20220315190228.1503866-2-wse@tuxedocomputers.com>
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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Thu, 17 Mar 2022 14:30:51 +0100
Message-ID: <CAJZ5v0iV5FvDxmYgoyQo_r39LYT2XL8wTujo_u=hu2n2BWdCRQ@mail.gmail.com>
Subject: Re: [PATCH] ACPI/backlight: Force backlight native for Clevo NL5xRU
 and NL5xNU
To:     Werner Sembach <wse@tuxedocomputers.com>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Mar 15, 2022 at 8:02 PM Werner Sembach <wse@tuxedocomputers.com> wrote:
>
> Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a working
> native and video interface. However the default detection mechanism first
> registers the video interface before unregistering it again and switching
> to the native interface during boot. This results in a dangling SBIOS
> request for backlight change for some reason, causing the backlight to
> switch to ~2% once per boot on the first power cord connect or disconnect
> event. Setting the native interface explicitly circumvents this buggy
> behaviour by avoiding the unregistering process.
>
> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/acpi/video_detect.c | 75 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
>
> diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
> index 4f64713e9917..becc198e4c22 100644
> --- a/drivers/acpi/video_detect.c
> +++ b/drivers/acpi/video_detect.c
> @@ -415,6 +415,81 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
>                 DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
>                 },
>         },
> +       /*
> +        * Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a
> +        * working native and video interface. However the default detection
> +        * mechanism first registers the video interface before unregistering
> +        * it again and switching to the native interface during boot. This
> +        * results in a dangling SBIOS request for backlight change for some
> +        * reason, causing the backlight to switch to ~2% once per boot on the
> +        * first power cord connect or disconnect event. Setting the native
> +        * interface explicitly circumvents this buggy behaviour, by avoiding
> +        * the unregistering process.
> +        */
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xRU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
> +               DMI_MATCH(DMI_BOARD_NAME, "NL5xRU"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xRU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "SchenkerTechnologiesGmbH"),
> +               DMI_MATCH(DMI_BOARD_NAME, "NL5xRU"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xRU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "Notebook"),
> +               DMI_MATCH(DMI_BOARD_NAME, "NL5xRU"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xRU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
> +               DMI_MATCH(DMI_BOARD_NAME, "AURA1501"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xRU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
> +               DMI_MATCH(DMI_BOARD_NAME, "EDUBOOK1502"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xNU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
> +               DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xNU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "SchenkerTechnologiesGmbH"),
> +               DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
> +               },
> +       },
> +       {
> +       .callback = video_detect_force_native,
> +       .ident = "Clevo NL5xNU",
> +       .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "Notebook"),
> +               DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
> +               },
> +       },
>
>         /*
>          * Desktops which falsely report a backlight and which our heuristics
> --

Applied as 5.18 material, thanks!