On Wednesday, July 18, 2018 8:46:55 PM CEST Alex Hung wrote:
> Some ThinkPad systems have a power-saving feature that turns off HDMI
> audio device in Windows, but NVidia Linux driver does not support this
> feature. As a result, HDMI audio will not work on Linux.
>
> A BIOS workaround is added with an OEM_OSI string
> "Linux-Lenovo-NV-HDMI-Audio" to power on NVidia HDMI audio when booting.
>
> The form of the OEM _OSI strings is defined by each OEMs and is
> discussed in Documentation/acpi/osi.txt.
>
> Signed-off-by: Alex Hung <alex.hung@xxxxxxxxxxxxx>
> ---
> drivers/acpi/osi.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/acpi/osi.c b/drivers/acpi/osi.c
> index 8a8f435..b2a16ed 100644
> --- a/drivers/acpi/osi.c
> +++ b/drivers/acpi/osi.c
> @@ -66,6 +66,14 @@ osi_setup_entries[OSI_STRING_ENTRIES_MAX] __initdata = {
> * be removed if both new and old graphics cards are supported.
> */
> {"Linux-Dell-Video", true},
> + /*
> + * Linux-Lenovo-NV-HDMI-Audio is used by BIOS to power on NVidia's HDMI
> + * audio device which is turned off for power-saving in Windows OS.
> + * This power management feature observed on some Lenovo Thinkpad
> + * systems which will not be able to output audio via HDMI without
> + * a BIOS workaround.
> + */
> + {"Linux-Lenovo-NV-HDMI-Audio", true},
> };
>
> static u32 acpi_osi_handler(acpi_string interface, u32 supported)
>
Applied, thanks!
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
