On 04/12, Harry Wentland wrote: > > > On 2024-04-12 16:22, Harry Wentland wrote: > > > > > > On 2024-04-12 12:26, Melissa Wen wrote: > >> On 04/12, Joshua Ashton wrote: > >>> > >>> > >>> On 4/11/24 3:26 PM, Melissa Wen wrote: > >>>> On 04/10, Joshua Ashton wrote: > >>>>> The comment here states "no OGAM in DPP since DCN1", yet that is not > >>>>> true. > >>>>> > >>>>> Testing on an RX 7900XTX (dcn32), it actually does exist in hardware and > >>>>> works fine. > >>>>> My best guess is the comment is confused with OGAM ROM for DPP, rather > >>>>> than OGAM RAM. > >>>>> > >>>>> I did not test dcn35/351 as I do not have that hardware, but I assume > >>>>> the same follows there given the seemingly erroneous comment. > >>>>> Someone at AMD should check that before merging this commit. > >>>> > >>>> hmm... I don't have any of these hw versions, but AFAIU if there is > >>>> ogam/blend lut block in dcn32, the helper implementation for programming > >>>> it properly (i.e. dpp_program_blnd_lut) is also missing here: > >>>> - > >>>> https://gitlab.freedesktop.org/agd5f/linux/-/blob/amd-staging-drm-next/drivers/gpu/drm/amd/display/dc/dpp/dcn32/dcn32_dpp.c#L125 > >>>> right? So, it's good if AMD people can check it too. > >>>> > >>>> Melissa > >>> > >>> Hmm, yes. But, see dcn32_set_mcm_luts, that seems to handle per-plane > >>> blend > >>> + shaper + 3D LUT state which is equivalent to what existed before? > >> > >> oh, cool! nice finding. blnd_lut is set on plane state, but programmed > >> on MPC now. > >> > >> But I see the color pipeline changed in many stages from this version: > >> - shaper + 3dlut before **or** after blending, but not before **and** > >> after? > >> - where post-blending gamut_remap_matrix is located now in this > >> pipeline with mpcc postblend_1dlut and shaper+3dlut with mutable > >> position? > >> I guess something like: > >> - [shaper -> 3dlut -> blnd_lut] -> ctm -> regamma ?? > > > > [1dlut -> 3dlut -> 1dlut] is now a movable block, called Movable CM > > (color management), or MCM for short. It can occur before blending or > > after. Because of that it moved to MPC (multi-plane combiner). > > > > If it's positioned for pre-blending it looks like this: > > > > DPP -> MCM -> BLND -> Blending -> Gamut Remap -> Out Gam -> OPP -> ... > > > > If it's positioned for post-blending it looks like this: > > > > DPP -> BLND -> Blending -> MCM -> Gamut Remap -> Out Gam -> OPP > > > > This is the case since DCN 3.2. > > > > Because of that you don't have an ogam_ram in dpp anymore for DCN 3.2 > > and newer. > > > >>> > >>> Therefore, I think I am actually wrong with enabling the ogam_ram in DPP > >>> cap > >>> here, and the right solution is to change the check for exposing the > >>> property to account for these LUTs being available per-plane with mcm. > >>> > >>> (what is mcm btw...? lots of acronyms and stuff moving around in hw hehe) > >> > >> yes, shaper, 3dlut, blend_lut don't seem DPP caps anymore. MCM looks > >> like a component of MPC, so I think we need new mpc.color caps to > >> describe them properly (?) > >> > >> I also didn't find in the Linux/AMD glossary or code comment that > >> describe what MCM is... > >> > >>> > >>> What's a good way for us to check for that? Seems like the caps don't help > >>> much there. We could check for the literal function ptr I guess...? > >>> > >>> What are your thoughts, Harry and Melissa? > >> > > > > I wonder if it makes sense to add an mcm cap to mpc_color_caps. Will need to > > chat with some people about that. > > > > I dug through the code a bit and talked with our resident expert. It looks > like all the programming for in_shaper_func, lut_3d_func, and blend_tf should > still work and assume a fixed pre-blending mcm, which is what we want.
Hi Harry, Thank you for explaning the latest changes in the color pipeline. Since MCM is fixed pre-blending in the current dcn32 driver: 1. I understand that the implementation for post-blending shaper/3dlut isn't available in the current dcn32 driver, right? 2. Does the dcn32 hardware itself support the configuration of both pre- and post-blending shaper/3dlut at the same time? Or, for example, dcn32 will advertise two color pipelines: one with pre-blending 3dlut and no post-blending, and another without pre-blending and only post-blending 3dlut? Melissa > > Caps don't really reflect MCM very well yet. We could either add an mcm > flag to mpc_color_caps or simply check that DCN is 3.2 or newer: > amdgpu_ip_version(adev, DCE_HWIP, 0) >= IP_VERSION(3, 2, 0) > > Harry > > > Harry > > > >> yeah, AFAIK color caps values are manually set and may contain > >> misleading information. I'm unsure that using function ptr would solve > >> the issue of having undocumented caps introduced to the color pipeline, > >> such as MCM, but your suggestion seems more reliable. > >> > >> Anyway, the timing where the color pipeline was merged didn't help, but > >> if new caps and functions are not documented and the DM handles are not > >> updated accordingly, we will have the same issue in the future. > >> For example, I see two new ptrs were introduced and implemented here: > >> - https://gitlab.freedesktop.org/agd5f/linux/-/commit/a820190204aef > >> - https://gitlab.freedesktop.org/agd5f/linux/-/commit/90f33674a0756 > >> and we would need to update the DM color mgmt anyway to check these > >> new/unknown functions. > >> > >> Seems okay if we check program_1dlut instead of ogam_ram caps, but what > >> should we do for dpp/mpc shaper+3d lut in set_mcm_luts? I mean, should > >> we enable plane or CRTC shaper+3dlut on DM? x_X > >> > >> Anyway, thanks for all these findings! > >> > >> I would like to hear more from AMD too. > >> > >> Melissa > >> > >>> > >>> - Joshie 🐸✨ > >>> > >>>> > >>>>> > >>>>> Signed-off-by: Joshua Ashton <jos...@froggi.es> > >>>>> > >>>>> Cc: Harry Wentland <harry.wentl...@amd.com> > >>>>> Cc: Xaver Hugl <xaver.h...@gmail.com> > >>>>> Cc: Melissa Wen <m...@igalia.com> > >>>>> Cc: Ethan Lee <flibitijib...@gmail.com> > >>>>> --- > >>>>> drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c | 2 +- > >>>>> drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c | 2 +- > >>>>> .../gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c | 2 +- > >>>>> 3 files changed, 3 insertions(+), 3 deletions(-) > >>>>> > >>>>> diff --git > >>>>> a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c > >>>>> b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c > >>>>> index 9aa39bd25be9..94f5d2b5aadf 100644 > >>>>> --- a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c > >>>>> +++ b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c > >>>>> @@ -2182,7 +2182,7 @@ static bool dcn32_resource_construct( > >>>>> dc->caps.color.dpp.dgam_rom_for_yuv = 0; > >>>>> dc->caps.color.dpp.hw_3d_lut = 1; > >>>>> - dc->caps.color.dpp.ogam_ram = 0; // no OGAM in DPP since DCN1 > >>>>> + dc->caps.color.dpp.ogam_ram = 1; > >>>>> // no OGAM ROM on DCN2 and later ASICs > >>>>> dc->caps.color.dpp.ogam_rom_caps.srgb = 0; > >>>>> dc->caps.color.dpp.ogam_rom_caps.bt2020 = 0; > >>>>> diff --git > >>>>> a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c > >>>>> b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c > >>>>> index 25ac450944e7..708d63cc3f7f 100644 > >>>>> --- a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c > >>>>> +++ b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c > >>>>> @@ -1861,7 +1861,7 @@ static bool dcn35_resource_construct( > >>>>> dc->caps.color.dpp.dgam_rom_for_yuv = 0; > >>>>> dc->caps.color.dpp.hw_3d_lut = 1; > >>>>> - dc->caps.color.dpp.ogam_ram = 0; // no OGAM in DPP since DCN1 > >>>>> + dc->caps.color.dpp.ogam_ram = 1; > >>>>> // no OGAM ROM on DCN301 > >>>>> dc->caps.color.dpp.ogam_rom_caps.srgb = 0; > >>>>> dc->caps.color.dpp.ogam_rom_caps.bt2020 = 0; > >>>>> diff --git > >>>>> a/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c > >>>>> b/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c > >>>>> index 8a57adb27264..053e8ec6d1ef 100644 > >>>>> --- a/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c > >>>>> +++ b/drivers/gpu/drm/amd/display/dc/resource/dcn351/dcn351_resource.c > >>>>> @@ -1841,7 +1841,7 @@ static bool dcn351_resource_construct( > >>>>> dc->caps.color.dpp.dgam_rom_for_yuv = 0; > >>>>> dc->caps.color.dpp.hw_3d_lut = 1; > >>>>> - dc->caps.color.dpp.ogam_ram = 0; // no OGAM in DPP since DCN1 > >>>>> + dc->caps.color.dpp.ogam_ram = 1; > >>>>> // no OGAM ROM on DCN301 > >>>>> dc->caps.color.dpp.ogam_rom_caps.srgb = 0; > >>>>> dc->caps.color.dpp.ogam_rom_caps.bt2020 = 0; > >>>>> -- > >>>>> 2.44.0 > >>>>> >
