Re: [PATCH 2/7] Revert "ACPI / OSI: Add OEM _OSI string to enable NVidia HDMI audio"

From: Lyude Paul
Date: Thu Dec 10 2020 - 13:01:56 EST


Hi, bumping the discussion again here because we just ran into this again, as we
just had a laptop OEM try to fix another issue by adding an OSI check for these
strings instead of helping us fix the issue in nouveau. Note as well the issue
I'm referring to is entirely independent of runtime D3, so we just got runtime
D3 broken again because of these hacks.

Why hasn't this patch been accepted into the kernel? These were added without
any sort of discussion with nouveau developers, and nouveau is the canonical
nvidia driver in the Linux kernel. These strings shouldn't be here without
discussion with the relevant driver maintainers, and need to be removed.

On Wed, 2019-08-14 at 23:31 +0200, Karol Herbst wrote:
> This reverts commit 887532ca7ca59fcf0547a79211756791128030a3.
>
> We have a better solution for this: b516ea586d717
>
> And same as with the last commit: "NVidia Linux driver" that's Nouveau, any
> out of tree driver does _not_ matter. And with Nouveau all of this works even
> though it required a proper fix first, but we have that now.
>
> Signed-off-by: Karol Herbst <kherbst@xxxxxxxxxx>
> CC: Alex Hung <alex.hung@xxxxxxxxxxxxx>
> CC: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> CC: Dave Airlie <airlied@xxxxxxxxxx>
> CC: Lyude Paul <lyude@xxxxxxxxxx>
> CC: Ben Skeggs <bskeggs@xxxxxxxxxx>
> ---
>  drivers/acpi/osi.c | 8 --------
>  1 file changed, 8 deletions(-)
>
> diff --git a/drivers/acpi/osi.c b/drivers/acpi/osi.c
> index 9b20ac4d79a0..56cc95b6b724 100644
> --- a/drivers/acpi/osi.c
> +++ b/drivers/acpi/osi.c
> @@ -53,14 +53,6 @@ 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)

--
Sincerely,
Lyude Paul (she/her)
Software Engineer at Red Hat

Note: I deal with a lot of emails and have a lot of bugs on my plate. If you've
asked me a question, are waiting for a review/merge on a patch, etc. and I
haven't responded in a while, please feel free to send me another email to check
on my status. I don't bite!