On 11/7/18 10:40 AM, Deucher, Alexander wrote: > FWIW there is a common property patch: > > https://patchwork.kernel.org/patch/10606697/ > > When should try and be compatible so we can transition. > > > Alex Thanks for the heads up. I remember seeing the i915 patch but I missed the common property one. It's a shame that this isn't already in. Sharing the same property name might work for compatibility ("max bpc"). The implementation relies on the same min/max range, the only thing that would change with that would be swapping out the attach with drm_connector_attach_max_bpc_property down the line. > > ------------------------------------------------------------------------ > *From:* amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> on behalf of > Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> > *Sent:* Wednesday, November 7, 2018 9:56:54 AM > *To:* amd-gfx@xxxxxxxxxxxxxxxxxxxxx > *Cc:* Kazlauskas, Nicholas > *Subject:* [PATCH 1/2] drm/amdgpu: Add "max_bpc" connector property > [Why] > Many panels support more than 8bpc but some modes are unavailable while > running at greater than 8bpc due to DP/HDMI bandwidth constraints. > > Support for more than 8bpc was added recently in the driver but it's > defaults to the maximum supported bpc - locking out these modes. > > This should be a user configurable option such that the user can select > what bpc configuration they would like. > > [How] > Introduce the "max_bpc" connector property so the user can limit the > maximum bpc for the panel. It ranges from 8 to 16. > > This doesn't directly set the preferred bpc for the panel but this > convetion is already in use for other drivers. > > Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 5 +++++ > drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h | 2 ++ > 2 files changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > index 7d6a36bca9dd..83dadf5b85e0 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > @@ -626,6 +626,11 @@ int amdgpu_display_modeset_create_props(struct > amdgpu_device *adev) > "dither", > amdgpu_dither_enum_list, sz); > > + adev->mode_info.max_bpc_property = > + drm_property_create_range(adev->ddev, 0, "max_bpc", 8, 16); > + if (!adev->mode_info.max_bpc_property) > + return -ENOMEM; > + > if (amdgpu_device_has_dc_support(adev)) { > adev->mode_info.freesync_property = > drm_property_create_bool(adev->ddev, 0, > "freesync"); > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h > b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h > index 1627dd3413c7..c39af5d79608 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h > @@ -338,6 +338,8 @@ struct amdgpu_mode_info { > struct drm_property *audio_property; > /* FMT dithering */ > struct drm_property *dither_property; > + /* maximum number of bits per channel for monitor color */ > + struct drm_property *max_bpc_property; > /* it is used to allow enablement of freesync mode */ > struct drm_property *freesync_property; > /* it is used to know about display capability of freesync mode */ > -- > 2.17.1 > > _______________________________________________ > amd-gfx mailing list > amd-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/amd-gfx Nicholas Kazlauskas _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
