| Message ID | 20220517152331.16217-6-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/kms: Stop registering multiple /sys/class/backlight devs for a single display | expand |
Reviewed-by: Lyude Paul <lyude@redhat.com> Also, ack on this being pushed to drm-misc, along with any other patches I r-b On Tue, 2022-05-17 at 17:23 +0200, Hans de Goede wrote: > Before this commit when we want userspace to use the acpi_video backlight > device we register both the GPU's native backlight device and acpi_video's > firmware acpi_video# backlight device. This relies on userspace preferring > firmware type backlight devices over native ones. > > Registering 2 backlight devices for a single display really is > undesirable, don't register the GPU's native backlight device when > another backlight device should be used. > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/gpu/drm/nouveau/nouveau_backlight.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c > b/drivers/gpu/drm/nouveau/nouveau_backlight.c > index daf9f87477ba..f56ff797c78c 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c > +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c > @@ -34,6 +34,8 @@ > #include <linux/backlight.h> > #include <linux/idr.h> > > +#include <acpi/video.h> > + > #include "nouveau_drv.h" > #include "nouveau_reg.h" > #include "nouveau_encoder.h" > @@ -404,6 +406,11 @@ nouveau_backlight_init(struct drm_connector *connector) > goto fail_alloc; > } > > + if (acpi_video_get_backlight_type(true) != acpi_backlight_native) { > + NV_INFO(drm, "Skipping nv_backlight registration\n"); > + goto fail_alloc; > + } > + > if (!nouveau_get_backlight_name(backlight_name, bl)) { > NV_ERROR(drm, "Failed to retrieve a unique name for the > backlight interface\n"); > goto fail_alloc;
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c index daf9f87477ba..f56ff797c78c 100644 --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c @@ -34,6 +34,8 @@ #include <linux/backlight.h> #include <linux/idr.h> +#include <acpi/video.h> + #include "nouveau_drv.h" #include "nouveau_reg.h" #include "nouveau_encoder.h" @@ -404,6 +406,11 @@ nouveau_backlight_init(struct drm_connector *connector) goto fail_alloc; } + if (acpi_video_get_backlight_type(true) != acpi_backlight_native) { + NV_INFO(drm, "Skipping nv_backlight registration\n"); + goto fail_alloc; + } + if (!nouveau_get_backlight_name(backlight_name, bl)) { NV_ERROR(drm, "Failed to retrieve a unique name for the backlight interface\n"); goto fail_alloc;
Before this commit when we want userspace to use the acpi_video backlight device we register both the GPU's native backlight device and acpi_video's firmware acpi_video# backlight device. This relies on userspace preferring firmware type backlight devices over native ones. Registering 2 backlight devices for a single display really is undesirable, don't register the GPU's native backlight device when another backlight device should be used. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/gpu/drm/nouveau/nouveau_backlight.c | 7 +++++++ 1 file changed, 7 insertions(+)